14 Oct 2021: The People Behind the New Best HIOKI Digital Multimeter DT4261

The People Behind the New HIOKI Digital Multimeter DT4261


Article written by Jessie Goh (Intern)


The new HIOKI Digital Multimeter is like no other.

Supporting measurements up to DC 2000V, wireless features, and having the ability to analyse harmonics in the field among other key features – the new HIOKI DT4261 is powerful. Unlike previous models, the DT4261 far exceeds expectations with its multiplied efficiency and superb performance. This is the digital multimeter that sets new standards as the engineer’s new best friend.

All of this is no wonder, as the new digital multimeter is specially handcrafted by our meticulous engineers with the rugged engineer in mind. But even so, the DT4261 is a digital multimeter that appeals to both seasoned and entry engineers. This is a product so good a 3rd year engineering undergraduate (also Hioki's Intern of 3 months) like myself silently (not so silently) wishes to get my hands on the multimeter for my university lab projects.

The DT4261 has in itself a certain charm that numbers and statistics cannot describe. With that, let us walk through the creation of DT4261, with a rare interview with the people behind this new HIOKI best digital multimeter: DT4261 Development Project Leader Mr. Takeaki Miyazawa, Hardware Team Leader Mr. Yusuke Abe and Product Marketing Team Leader Mr. Kohei Narita from HIOKI E. E. Corporation. These are some highlights of our conversation.

Mr. Takeaki Miyazawa will be denoted by (TM), Mr. Yusuke Abe denoted by (YA), and Mr. Kohei Narita will be denoted by (KN).


Thank you for agreeing to do this interview with us! Can you share with us more about the reasons behind creating the DT4261 and what were your motivations?

TM: So far, HIOKI did not have a wireless digital multimeter. Therefore, our development team wished to launch a multi-meter with such wireless capabilities. One of the major motivations of creating the DT4261 is to have an advantage over other competitors with this wireless feature. Another motivation of creating the DT4261 was the increasing need to measure high voltages in the photovoltaic (PV) systems sector, and HIOKI would want to create a digital multimeter that better suits the needs of that sector. To support higher voltages, we will also be launching the new optional P2000 probe that can be used with the DT4261, in December later this year. These are the motivations for creating the new DT4261.

HIOKI DT4261 with P2000 Probe

High Voltage Probe P2000
(to be launched in December 2021)

What kind of applications and industry are the P2000 and DT4261 meant for?

KN: The main target for the P2000 is the electrical maintenance industry, such as power utility contractors. Apart from electrical maintenance, the solar PV market is one of the key target markets for the P2000.


What was the project journey like and how did your team go about creating the DT4261?

TM: Firstly, the team decided on the concept of DT4261 and what DT4261 should have. At that point, the most important feature we wanted to have was the wireless capability. Secondly, we had to think on how the DT4261 is to be used by end-users. From that point of view, we decided that the DT4261 must be used on-site and as such, it must not break easily and be designed for ruggedness. With these concepts in mind, we designed the DT4261 for different uses, which help to pinpoint specific features of the DT4261 such as it being waterproof, dustproof and having the shutter safety feature.

YA: The development of DT4261 lasted from February 2019 till now. Apart from what was said earlier, we wanted to hear our customer’s feedback for the DT425X and DT428X multimeters. From our customer’s feedback, we have learnt that the shutter safety function is one of the most wanted features in a multi-meter. However, if the safety shutter function is incorporated, the multi-meter will not be able to conduct open circuit checking due to hardware limitations. To overcome this difficulty, we have included a fuse checking feature, to improve safety and reliability on the new DT4261. In summary, our project journey first started off with deciding on the most important feature, how it is being used by end-users, and listening to customer feedback.

Thank you for sharing more about your project journey. Then, can you share with us some challenges and difficulties faced in creating the DT4261?

YA: One of the biggest challenges faced in the development of DT4261 was meeting the IP54 standards, as it is our first time working with such high definitions of IP54 with our digital multimeters. Especially for the waterproof standards, which entailed the digital multimeter not getting damaged under wet conditions. This proved to be difficult due to input holes on the body required for test probes. To counter this, we made the open body holes water repellent to accommodate waterproofness and the shutterfunctions, as well as changes to the button rubber shape. To achieve waterproofness, we also reviewed the designs of all existing digital multimeter models.

A lot has been done to accommodate all these ideas. Likewise then, what did you enjoy the most about creating the DT4261? Or perhaps any memorable moments you would like to recount?

YA: The creation of the DT4261 was really memorable firstly because we had a lot of younger engineers with us for this project. They have been really enthusiastic and given us a lot of new suggestions and ideas, such as fuse check functions. All of which we did our best to include all of it in the new DT4261. Hopefully this motivates them.

TM: Secondly, as we have reviewed the designs of all existing HIOKI digital multimeters, there are a lot of features we can incorporate. Product evolutions are usually quite simple, but instead this time we decided to do something new by adding many new things. As such, we needed to evaluate deeper which resulted in a rather challenging journey with lots of failures, refinements and problem solving. This made us a little worried that we might not be able to make it to the launch deadline. Fortunately, we were able to make it in time!

That must have been quite the journey! Among all these features, what kind of engineer was the DT4261 created for?

TM: As our team had a lot of highly motivated and younger engineers, we had a lot of ideas for the DT4261. Despite the many challenges, we were able to overcome all of them thanks to their resilience and innovative thinking. Not only that, these engineers were perfectionists as well. An example would be the integrated cap feature on the L9300 Test Probe. How to slide the cap, was also an idea of theirs. These ideas were being thought about very thoroughly, such as whether it was worth it for the end-users. The DT4261 is also very precise and accurate, and would suit engineers who are perfectionists.

“DT4261 is not only a wireless multimeter, but also a durable multimeter with safer features. This is ideal for more senior engineers. " – Mr. Takeaki Miyazawa, DT4261 Development Project Leader, HIOKI E. E. Corporation

Since the DT4261 is the first wireless digital multimeter that HIOKI has created, are you worried that more senior engineers will not be able to use or appreciate the new DT4261?

TM: Additionally, senior engineers would use oscilloscopes in their work, which is not handy and cannot be brought onto the field. This is where digital multimeters are useful. They can display waveforms like the oscilloscope, and are also handy. Even though these waveforms are simpler ones, being able to see such waveforms is a valuable feature for senior engineers.

YA: While there are more features that are appealing to younger engineers, there will be more younger engineers in the industry as time passes. Younger engineers do not have as much experience, and to acquire suitable experience, they require suitable tools.

“Therefore, the DT4261 with wireless capability can be a suitable tool for younger engineers to use and grow. " – Mr. Yusuke Abe, DT4261 Hardware Team Leader, HIOKI E. E. Corporation

As we all know, HIOKI’s digital multimeters play a key role in the branding of the HIOKI we know today. In what way does the DT4261 contribute to the legacy of HIOKI’s digital multimeters?

TM: For our digital multimeters thus far, we have only focused on hardware design, such as making it tough and durable. We listen to customer’s feedback attentively as well, but it usually is also aspects of hardware. This multimeter is a lot more special, as we have incorporated wireless communicative features that enable users to use onsite, which improves data transfer of site measurements.


“From this, DT4261 is another starting point in HIOKI’s multimeter history, in terms of more efficient data transfer and convenience for users. “ – Mr. Takeaki Miyazawa, DT4261 Development Project Leader, HIOKI E. E. Corporation

You have shared a lot about the functions of the DT4261 and since you have brought along the multimeter, will you share with us some design improvements of the DT4261?

YA: There are 3 main design improvements. Firstly, to make the multimeter easier to grab, we have redesigned the DT4261 to have a slimmer and curved body.

Secondly, we made changes to the rotary switch. The rotary switch in existing digital multimeters protrudes out of the body, which results in unstable rocking when placed face down. The DT4261’s rotary switch is flushed against its body, resulting in a flat multimeter front surface. As such, there will be no unstable rocking when the DT4261 is placed on the table like this.



Thirdly, the battery box on the rear end. So far for existing models, we have to use screws to open the lid. However with this new design, users can easily open the battery box with a coin. This may be a small point, but when thinking about users on the field, there is a higher chance of users having coins on them compared to screwdrivers. This will help make it easier for them to open the battery box on the digital multimeter on site.


Many thanks for sharing so much about the DT4261. Are there any more things you hope to share with everyone?

KN: Last but not least, we would like to talk about the optional P2000 Probe. With the P2000 probe, the DT4261 can measure up to DC 2000 V. This is under CAT III specifications. This is the world’s first multi-meter that can measure up to DC 2000 V CAT III. The P2000 probe will be launched in December. Users will not have any more concern about measurements up to DC 2000 V with the DT4261. We would like all of you to stay tuned for the P2000 Probe launch and we are convinced that you will welcome this combination of P2000 and DT4261.

TM: We believe that the DT4261 can contribute to better data transfer on site with its wireless communication ability. The wireless communication ability allows users to connect the DT4261 to their smartphones and tablets, using the GENNECT Cross application software. DT4261 with GENNECT Cross can display harmonics and waveforms onsite on the user’s mobile or tablet screen, which is efficient and effective for any maintenance engineer who works in the field.

The DT4261 will be released for Pre-Order on 15 October 2021 for Singapore, Malaysia, Vietnam, Thailand, Philippines and Indonesia regions. Click here to Pre-Order.


For more product information, please click on the links below:

Hioki Digital Multimeter DT4261 Product Introduction

Hioki Digital Multimeter DT4261 Product Information

Hioki Digital Multimeter DT4261 Catalog

Hioki High Voltage Probe P2000 

1 Oct 2021 : Hioki Launches Digital Multimeter DT4261

Hioki Launches Digital Multimeter DT4261

Bluetooth® to Improve Efficiency


The wait is over. Hioki Singapore  is pleased to announce the launch of Digital Multimeter DT4261.  To celebrate the 75 years of Hioki Digital Multimeters innovation, there will be a special pre-order launch on 15 October 2021, 10 00hrs. In addition to the DT4261, end users who registered their interest will also be given a complimentary Wireless Adapter Z3210 and limited edition DT4261 keychain.

Pre-order sales will take place from 15 October 2021 - 29 October 2021, and is opened to South East Asia countries.

The official launch will take place from 30 October 2021, and customer will only receive the limited edition keychain.

When the Wireless Adapter Z3210 is installed, Bluetooth® wireless communication is enabled. It will boost work efficiency in the field by entering your measured data directly into Excel templates. Furthermore, when using with the free GENNECT Cross mobile app, you can perform simple harmonic analysis.

Please find more details about the DT4261 here:
DT4261 Special Introduction Page

Development Background

At present, Hioki has been expanding our lineup of on-site measuring instruments that support Bluetooth® wireless communication in order to streamline electrical equipment inspection performed by electricians and maintenance technicians. The increase of efficiency cuts the costs of these technicians, but in addition, in certain regions like the home country of Hioki, Japan, the aging population and decline of skilled technicians in the labor force has become an issue. Partly due to this market environment, we at Hioki have focused on improvement of work efficiency using IoT.


1. Wireless Support: Excel Direct Input Function

When the Wireless Adapter Z3210 is installed, Bluetooth® wireless communication is enabled, opening the door to many innovations availed by Bluetooth®. One such innovation is the Excel Direct Input Function. We embedded this function in the Wireless Adapter itself. It enables direct transfer of measurement data to Excel® templates on your smartphone or tablet. This Excel Direct Input function will boost work efficiency by eliminating the bothersome task of entering data after returning from the field.


2. Harmonic Measurement

When combined with the free GENNECT Cross mobile app, you can perform simple harmonic analysis. Applications for this function include harmonic measurement of power conditioners for solar systems and problem analysis of power supply systems.


3. Excellent Dust and Water Resistance (compliant with the IP54 international standard)

Highly dust-proof and water-proof suited for rugged use.


4. Auto Fuse Check Function – Prevents Incorrect Current Measurement

When switching from the clamp function to the current function, a fuse disconnection check is automatically performed. This allows the user to know if the fuse is broken before current measurement, which prevents erroneous measurement.

Ensuring safety by preventing erroneous test lead insertion (terminal shutters)

Ensuring safety by preventing erroneous test lead insertion (terminal shutters)

Test Lead L9300 incorporate integrated caps for greater convenience and safety.

Test Lead L9300 incorporate integrated caps for greater convenience and safety.

6. Ensuring Safety through Mechanical Innovations for the Test Lead

Typically, technicians must be careful not to measure voltage while a test lead is plugged into the current terminal rather than the voltage. Otherwise the fuse to blow, ending in a fuse that needs to be replaced and lost man hours until the replacement. Hioki, however, solved this problem through innovation with the Middle Model Digital Multimeter DT4261. The multimeter’s terminal shutters are linked to the instrument’s rotary switch in way that blocks access to test lead terminals that aren’t being used. This makes it physically impossible to insert test leads into the wrong terminal.

In addition, Hioki’s new test lead now incorporates easily adjustable sleeve instead of a cap for greater convenience and safety. The design lets you change the measurement category simply by sliding the test lead’s protective finger guard up or down and locking into place. This makes it easier than ever to measure safely, and as an added bonus, you no longer have to worry about losing caps.

7. Supports Measurements up to DC 2000V for PV Solar Systems with P2000 Probe (to be released in December 2021)

The increasing prevalence of large Photovoltaic Systems comes with the increasing need of measuring voltages above DC 1000V. The DT4261 safely supports measurements between ground to DC 2000V (CAT III 2000V, CAT IV 1000V) with the optional DC High Voltage Probe P2000.

P2000 to be released in December 2021.

More about DC High Voltage P2000 Probe

8. Multifaceted Functionality and Performance for a Variety of Tasks

•  Ability to withstand a 1m height drop onto concrete (drop-proof design)
•  Broad operating temperature range of -25°C to 65°C
•  Automatic detection of DC and AC voltages (AUTO V function)
•  Visual warning of excessive input via red backlight
•  Visual indication of HOLD operation via orange light

Engineers' NEW Best Multimeter

We have reshuffled and curated our list of Digital Multimeters into a chart for your viewing convenience. Up to date, we have a total of 12 Digital Multimeters specially designed to suit your every need.  With the Good, Better, Best, Supreme concept, we hope that this will provide customers a better idea when choosing the right multimeters for their application.


Click here for more detailed DT4261 specifications

Main Uses

  • Electrical equipment maintenance, verification and troubleshooting in electrical work
  • Large Commercial Solar Farms


Digital Multimeter DT4261
Digital Multimeter DT4261 Kit (set with Wireless Adapter Z3210)
Wireless Adapter Z3210: accessory

Download the catalog here:
DT4200 Series

29 Sep 2021 : HIOKI Clamp On Power Logger PW3360-20 for Energy Management of Chiller Plant

HIOKI Clamp On Power Logger PW3360-20 for Energy Management of Chiller Plant

What is Energy Management?

Energy Management refers to the process of monitoring, controlling and conserving energy in a building or organization [1]. The driving force for energy management is the conservation of energy as it affects energy costs, emission targets and legislation requirements. Figure 1.0 shows the steps involved in energy management for energy efficiency optimization, in a cyclical process.


Figure 1.0 Energy Management Steps – a Continuous Cycle



The Importance of Energy Management of Chiller Plant

In industrial factories and commercial buildings, air conditioning energy consumption accounts for over 50% of the energy cost [2]. The chiller plant acts as the centralized cooling system to provide air conditioning for buildings and consists of four main components: a compressor, condenser, expansion valve, and evaporator (Figure 2.0).


Figure 2.0 Main Components of a Chiller


Due to the high cost of energy consumption, chiller plant energy efficiency is optimized through energy management to save cost. In addition, high rates of energy consumption of air conditioning negatively impact the environment, as illustrated in Figure 3.0.


Figure 3.0 Air Conditioning Energy Consumption Impact on Environment 


Measurement Instrument for Energy Audit in Energy Management

In any Measurement and Verification (M&V) method to assess the Energy Efficiency (EE), accurately quantifying EE savings is a critical yet technically challenging aspect. One of the main concerns in an energy audit is the uncertainty (doubt) of the measurement instrument. This can be caused by several sources such as repeatability, reproducibility, stability, bias, drift, resolution, reference standard and reference standard stability [3].

Measurement uncertainty can affect risk assessment and decision-making, impacting financial goals, safety, and quality [4]. Therefore, there is a need for regulatory guidelines to manage and mitigate this uncertainty. Figure 4.0 illustrates an example of the effect of uncertainty on the quantified EE savings, whereby the uncertainty is mitigated by decreasing the reported savings for conservative reporting.


Figure 4.0 Effect of Uncertainty on Energy Efficiency Savings


The Building and Construction Authority (BCA) Green Mark (Singapore) for Existing Non- Residential Buildings 2017 stipulates a 5% uncertainty for the instrumentation installed to calculate the resultant chiller plant operating system efficiency (kW/RT) [5]. These include sensors, any signal conditioning, a data acquisition system, and wiring connecting the components.


Green Mark Requirements for M&V Instrumentation of Chiller Water System



HIOKI Power Logger PW3360 for Energy Management of Chiller Plant

Hioki's Power Logger PW3360-20 has the highest accuracy among all the available power loggers in the market, with a combined active power of + 0.6% rdg. + 0.11%f.s. (inclusive of 500A clamp-on sensor 9661). This important feature means the total uncertainty will not exceed the 5% limit inclusive of other instruments (Data Logger + Temperature + Flow sensors).

HIOKI Power Logger PW3360
HIOKI Clamp On Sensor 9661

HIOKI Power Logger PW3360

HIOKI Clamp On Sensor 9661

In Energy Audit measurement, Energy Service Companies (ESCO) will use their portable power loggers, which are well-calibrated. However, there are some facilities with fixed power meters, but these meters' maintenance status can be doubtful. All the power measurements for the energy audit are at the chiller plant control panel (Figure 5.0).


Figure 5.0 Energy Audit Measurements are taken at the Chiller Control Panel


For energy management analysis and data demonstration purposes, this application note will use an example of a two-day duration data from a Water-Cooled Chilled-Water Plant system, which is most commonly used in our tropical climate. This system utilizes water as the cooling agent for the gaseous refrigerant in the condenser. For actual energy audit, a two weeks data measurement is taken at one minute interval and recorded to the 3rd decimal digit [6] (Figure 6.0).

Figure 6.0 Example of Screen Display on PW3360

Figure 7.0 shows the data measurement analysis process flow of the two days data collected for this application note. However, only Part B data will be shown in this application note as this is most relevant to energy management of a chiller plant.


Figure 7.0 Process Flow of Energy Management Data Analysis


The values obtained in Part A are used in the following formulas below to calculate the parameters in Part B.


Total Power Consumption Cooling Load, (kW)
Sum (PCH + PCH pump + PCD pump + PCT)


Cooling Load, (kW)
CWater * QCHW * ΔT(CHWR-CHWS), where CWater = Specific Heat Capacity of Water (constant value)


Cooling Load, (RT)
Cooling Load (kW) / TR (kW) , where TR = Tons of Refrigeration (constant value)


Heat Rejection Condenser Load, (kW)
CWater * QCDW * ΔT(CDWR-CDWS), where CWater = Specific Heat Capacity of Water (constant value)


Plant Efficiency, (kW/RT)
Total Power Consumption Cooling Load (kW) / Cooling Load (RT)


Heat Balance Error, (%)
Heatin – Heatout / Heatout x 100%
= (PCH + Cooling Load(kW)) – (Heat Rejection Condenser Load(KW)) / Heat Rejection Condenser Load(kW)) x 100%


i)  The constant value for the specific heat capacity of water is 4.19 kJ/kg/°C
ii)  The constant value of TR is 3.517kW (Defined as the heat transfer rate required to melt 1 ton (2000lbf) of ice at 32F in 1 day (24hr))



Figure 8.0 Daily Cooling Load Profile Over 24 Hours


Figure 8.0 shows the Cooling Load profile over 24 hours of both days. Day 1 cooling trend shows minimal fluctuations throughout the day, perhaps representing the weekend usage data trend. On the contrary, Day 2 data trend shows to be volatile throughout the day and a consistently higher cooling load usage between 7.00 am and 9.30 pm, representing a weekday usage trend. Usually, a two-week data with multiple line trends allow users to check for consistency in power consumption trend for weekdays and weekends. These multiple line trends are also needed to find the average instantaneous peak of the cooling load, which is required to determine the Green Mark efficiency rating category, as shown in Figure 9.0 below.


Figure 9.0 Green Mark Chiller Plant Efficiency Rating


Histogram distribution of the cooling load data (Figure 10.0) enables users to identify the most frequent cooling load occurrence; based on the two days' data, the two highest ranges are in 301RT - 400RT and 701RT - 800RT at 60.28% and 18.26%, respectively. The chiller with a cooling load within these two cooling load ranges will be the optimal choice for any future chiller replacement.


Figure 10.0 Histogram Distribution of Cooling Load


The chilled water plant efficiency profile by day over a 24-hour period (Figure 11.0) indicates a stable average trend around 0.6kW/RT - 0.7kW/RT throughout the day, except some outliers between 7.00 am and 7.30 am. The day's average, maximum, and minimum efficiency values are determined from the trend and used with the cooling load profile data to calculate the potential savings for any chiller replacement action.


Figure 11.0 Chilled Water Plant Efficiency Profile over 24 Hours


Based on the American Society of Heating, Refrigerating, and Air Conditioning Engineers (ASHRAE) chiller plant efficiency benchmark [7], the most desired efficiency is less than 0.85kW/RT.


ASHRAE Chiller Plant Efficiency Benchmark


In the Green Mark Platinum rating requirement, the chiller efficiency needs to be less than 0.68kW/RT for <500RT cooling load. The efficiency versus load distribution (Figure 12.0) shows the user the 'sweet spot' for the chiller to operate most efficiently. Day 1 data shows that the chiller can achieve an efficiency of < 0.68kW/RT between a cooling load range of approximately 300RT - 425RT with high consistency and occurrence. For day 2 however, it is observed that there are three distinct groups of cooling load in the range of 300RT - 800RT performing with an efficiency range of 0.6kW/RT - 0.7kW/RT. Therefore, there is no specific 'sweet spot'.


Figure 12.0 Efficiency vs Load Distribution by Day


Using the heat balance (HB) profile on both days (Figure 13.0) and the Green Mark M&V Instrumentation criteria (See below) for heat balance computation, the summary of the heat balance analysis is shown in Table 1.0. It shows that there's no issue with Day 1's sensor integrity as >80% of the heat balance data is within the ± 5% range while for Day 2, it fails the targeted 80% level and requires further investigation on the temperature sensor to conclude whether recalibration/ replacement of the sensor is required.


Figure 13.0 Heat Balance (HB) Profile by Day


Green Mark Criteria for Heat Balance (HB) Computation of Chiller Water System


Table 1.0 Summary Data for Computation of Heat Balance (HB) based on Green Mark



For more information on other Code of Practice related to the energy efficiency of HVAC, please refer to the following documents of Singapore’s Standard Code of Practice:

■  SS 591: Code of practice for long term measurement of central chilled water system energy efficiency

■  SS 530: Code of practice for energy efficiency standard for building services and equipment

■  SS 553: Code of practice for air-conditioning and mechanical ventilation in buildings

■  BCA Green Mark for existing non-residential buildings


Aside from all the valuable parameters measurement above that fulfil the measurement instrument requirement of 5% uncertainty, Hioki PW3360-20 also comes with various value-added features as below:

■  Attractive pricing, which is affordable in terms of features- to- pricing in the market (Please check with our Hioki sales representatives)

■  Compact size and lightweight


■  Power measurement range up to 300.00 W to 9.0000 MW

■  Continuous measurement with no gap (critical for power profile measurement)



■  Built-in HTTP function allowing users to configure and monitor the instrument from a browser and FTP server to download the data. Multiple PW3360-20 and LR8450 Memory HiLogger can be connected for real-time logging using GENNECT One free software.

■  Storage to 2GB SD Card (Maximum recording period of 1 year based on 1-minute interval)



Hioki's Power Logger PW3360-20 features give users the confidence to execute energy audit data measurement required in Energy Management of Chiller Plant. It also fulfils the highly regarded and internationally recognized Green Mark rating M&V Instrumentation criteria.


1. https://www.energylens.com/articles/energy-management

2. https://www.ijstr.org/final-print/jun2020/Electrical-Consumption-Balance-Of-Chillers-Cooling-Load.pdf

3. https://www.isobudgets.com/8-sources-of-uncertainty-in-measurement-for-every-uncertainty-budget/

4. https://www.isobudgets.com/why-measurement-uncertainty-is-important/

5. https://www.bca.gov.sg/greenmark/others/GM_ENRB_2017_simplified_criteria.pdf

6. https://www1.bca.gov.sg/docs/default-source/docs-corp-buildsg/sustainability/green-mark-enrb-2017-technical-guide.pdf 7. https://optimumenergyco.com/how-to-optimize-an-hvac-system/

16 Sep 2021 : They Are The Creators of the Award-Winning HIOKI Digital Multimeters DT4200 Series

They Are The Creators of the Award-Winning HIOKI Digital Multimeters DT4200 Series

The Secret Origin Story of Hioki Digital Multimeter DT4200 Series

This year marks 75 years of Hioki Multimeters’ history since the Japanese company launched the first tester, the model H Circuit Tester in 1946.  In 2013, Hioki launched the Hioki Digital Multimeter DT4200 series, which comprise of 7 models, including two multifunctional models for use in research and development of inverters and solar power systems, three standard models with functionality that has been optimized for on-site electrical work, and two pocket-sized models that combine enhanced portability with functionality that has been specialized for a range of applications. Till date, the DT4200 series has expanded to 11 models. One more addition will be added to the range on 1st October 2021, and it is believed that the latest model will boost customers’ work efficiency to another level, with the campaign tagline, “Multiplies Efficiency.”


Hioki First Tester in 1946 – the model H Circuit Tester

All models in the series feature a product design that maximizes operability and convenience to meet customer needs based on the product’s fundamental concept of empowering users to perform professional-grade work more quickly, as well as HIOKI’s commitment to bringing high-quality products developed and manufactured in the city of Ueda in Japan’s Shinshu region to customers worldwide. The series has been embraced by numerous customers since its launch.

In the year 2013, Hioki E.E. Corporation’s Digital Multimeter DT4200 Series has been honored with a 2013 Good Design Award from the Japan Institute of Design Promotion.

Hioki DT4200 Digital Multimeter Series Was
Awarded the Good Design Award in 2013



In their evaluation comments, the judges who selected the DT4200 series noted:

“The product is a line of digital multimeters that can be used in a variety of on-site electrical measurement applications. The instruments, which incorporate vertical and horizontal indentations to make it easy to wrap lead wires around them in either orientation in response to market research indicating that users tend to store the instrument by wrapping the lead wires around it with the test probes still attached, benefit from an easy-to-hold, stylish design that is not simply a square box. Shutters linked to the rotary switch used to select the function being used serve to close off measurement terminals that are not in use, preventing electric shocks and short-circuits caused by mistaken operation. Pocket models, which are designed so that they can be held with one hand, incorporate numerous creative touches such as a rotary switch designed so that it can be operated with one hand. We find that the products deliver exceptional designs that demonstrate even a common, widely used measuring instrument such as a digital multimeter can still be improved if designers put their minds to it.”

The Japan Institute of Design Promotion has been granting Good Design Awards as part of a comprehensive design evaluation and recommendation program for more than 50 years. HIOKI received its first Good Design Award in 1985, and the DT4200’s recognition marks the 57th time that the company has received the accolade (including two Long Life Design Awards) in 2013. Till date, the company has received a total of 76 of the accolades, the latest was the Memory HiLogger LR8450 in the year 2020.

Hioki Singapore Assistant Marketing Manager, Mr. Kevin Soh had the privilege to interview one of the creators of the Digital Multimeters DT4200 series, Mr. Seiji Onuma from Hioki E.E Coporation, to find out more about the secret story origins about the award-winning product. Mr. Kevin is denoted by (KS), while Mr. Onuma is denoted by (SO)  . The interview was done via email.


KS : Hi Mr. Onuma, thank you for accepting our interview! Can you share with us why did you design DT4200 series back in 2013?


OS:The reason was that the safety standards for digital multimeters had become stricter than before. Until then, HIOKI’s Digital Multimeters had been designed by other companies, and HIOKI had proposed the external design and specifications.


When the safety standards were modified, we decided to develop the entire Digital Multimeter series in-house. I had been involved in the product design of the 3244 Card Tester, 3245 Solar Tester, and 3246 Pencil Tester, so I was also involved in the new Digital Multimeter project from the beginning.



KS : What was the most memorable event when you design the DT4200 series?


OS:The DT series was the first to wear HIOKI blue, and it became the basis for the design image of HIOKI’s subsequent field measuring instruments (especially the clamp meter series). Initially, we were asked to use high-impact colors such as dark orange and red.


However, our design team proposed royal blue as the key color for the product, as it symbolizes the accuracy and high performance of HIOKI products. The HIOKI company logo itself was then based on the royal blue color and became all blue.


KS : What were your challenges when designing DT4200 series?


OS:We had a hard time expressing the features of each of the three models while giving them a common image as the DT series.


In addition, the external shape and blue parts common to the three models are not just a fashion statement or a mere differentiation from other companies’ products. For example, the inverted arches at the top and bottom of the product were designed to prevent the cable from collapsing even when the test lead is attached and wrapped haphazardly around the body. The shape of the blue rubber parts was carefully designed to prevent direct impact on the body of the product, no matter how it is dropped.


I will also like to share some of the design sketches  from the time of development here:

The  Design Sketches  Of  Hioki Digital Multimeter  DT4200series

The Actual Product



KS : Finally, can you share with us the rest of the team who had worked tirelessly together with you on the development of DT4200 series?  



OS:Definitely. These are the people who had worked together with me on the product. They are Mr. Tetsuya Nakamura & Mr. Yoshiyuki Miyazawa, who were both the  development leaders of the DT series. It is important to remember that it was not only the three of us, but also Mr. Mr. Toshio Heyishi, who was in charge of mechanical design, and many other people who helped create this wonderful product.


We have all moved on to other departments, but we are looking forward to the new digital multimeter that will be added into the series created by the new group of Hioki Engineers. Please support them as they had worked very hard in the development process to enrich life and society by offering a pleasant experience when the new digital multimeter is held and used.


(Mr. Seiji Onuma is now leading the marketing and promotions team. He oversees and creates new marketing communication materials and videos to promote Hioki brand and products.) 



Stay tuned to the launch of the NEW Digital Multimeter on 1st October 2021, Friday!  Follow us on the list of social media channels for the latest news! Celebrating 75 years of Hioki Multimeters’ Innovation! #MultipliesEfficiency

Hioki Singapore Facebook 

Hioki Singapore Instagram

Hioki Singapore LinkedIn

Hioki Singapore Youtube 


7 Sep 2021 : CM4002 and CM4003 AC Leakage Clamp Meter User Manual Wins Merit Award in the Industry Category at the Japan Manual Awards 2021

CM4002 and CM4003 AC Leakage Clamp Meter User Manual Wins Merit Award in the Industry Category at the Japan Manual Awards 2021

HIOKI is pleased to announce that the CM4002 and CM4003 AC Leakage Clamp Meter User Manual won a Merit Award (Industry category) at the Japan Manual Awards 2021, which was hosted by the Japan Technical Communicators Association (TC Association). The accolade marks the fourth consecutive year for HIOKI to win an award at the Japan Manual Awards. The manual was also nominated for Manual of the Year 2021, which will be announced at a TC Symposium in Kyoto in October.

The TC Association bestows Japan Manual Awards, whose goals include fostering improvement in the quality of manuals, to recognize exceptional manuals and user documentation that are easy for readers to understand.


The CM4002 and CM4003 User Manual was chosen for the Merit Award based principally on the following qualities:

■  The manual satisfies the requirements imposed by international standards.

■  The manual adopts a company A6-size format that's easy to handle while working.

■  QR Codes in the manual take readers to HIOKI's website, where they can find more detailed explanations.

Japan Manual Award Logo

Logo of the Japan Manual Award

CM4002 and CM4003 AC Leakage Clamp Meter User Manual (Cover)

CM4002 and CM4003 AC Leakage Clamp Meter User Manual (Cover)

In addition to Japanese and English, HIOKI publishes manuals for the products it sells in numerous languages and delivers them to customers worldwide. The company has made a series of improvements over time to ensure its manuals incorporate numerous illustrations and easy-to-understand language so that even customers who find themselves operating an electrical measuring instrument for the first time can do so safely and with a sense of familiarity after reading through the documentation.

HIOKI will draw encouragement from this honor as it continues to compile easy-to-understand user manuals that empower customers to use its products safely and correctly.

Japan Manual Awards received by HIOKI



Merit Award (Industry category) (and nomination for the Manual of the Year Award): CM4002 and CM4003 AC Leakage Clamp Meter User Manual



Manual of the Year 2020 (cowinner) and Merit Award (Industry category): LR8450 and LR8450-01 Memory HiLogger Quick Start Manual



Merit Award: CT6710 and CT6711 Current Probe User Manual



Excellence Award: MR6000 and MR6000-01 Memory HiCorder Quick Start Manual
Incentive Award: SM7420 Super Megohm Meter User Manual

Product Introduction

The AC Leakage Clamp Meter CM4001 series (including the CM4001, CM4002, and CM4003) makes it easy to measure current in complex electrical wiring in confined spaces thanks to a jaw (sensor) profile that is easy to slip between – and clamp around – wires. Moreover, the newly designed sensor unit can accurately detect miniscule leakage currents. The instruments also can connect wirelessly to mobile devices in the field to monitor leakage currents, contributing to the fast resolution of problems involving electric leaks.

The AC Leakage Clamp Meter CM4001 received an iF Design Award 2021 (Product Design Award, Industry/Tools category).


For more product information, please click on the links below:

AC Leakage Clamp Meter CM4001

AC Leakage Clamp Meter CM4002

AC Leakage Clamp Meter CM4003

Clamp Meter Series

1 Sep 2021 : HIOKI Launches New Power Analyzer PW8001 and AC/DC Current Sensors CT6872 and CT6873

HIOKI Launches New Power Analyzer PW8001 and AC/DC Current Sensors CT6872 and CT6873



Optimized for the Development of Compact, High-efficiency Devices, 8-channel Inputs that Provide World Class Flexibility and Accuracy


HIOKI E.E. CORPORATION is proud to announce its all new "Power Analyzer PW8001 and AC/DC Current Sensors CT6872 and CT6873." Shipments of both are scheduled to begin at the end of 2021.

The Power Analyzer PW8001 is the new flagship model that brings together Hioki’s full technological expertise of highly advanced analysis and multi-frequency accuracy to respond to modern demands for high-precision, wide frequency bandwidth, and highly stabile measurement. Its next-generation digital platform enables high-speed power analysis of up to an astounding eight channels. In addition, its new current sensor interface makes Hioki’s phase-correction technology, crowning Hioki’s current sensors with unrivaled accuracy in the market, even more reliable and easier to use by automating settings that would otherwise be done by hand.

The CT6872 (50 A current rating) and CT6873 (200 A current rating) are through-type current sensors with dramatically improved frequency bandwidth and noise-resistant performance based on our current market leading current sensors. It is ideal for evaluating compact, high-efficiency power supplies that are increasingly common in the areas of industrial equipment, data centers, and EVs (electric vehicles). Their performance are truly pronounced in the evaluation of high-speed switching power supplies equipped with next-generation power semiconductors composed of SiC (silicon carbide) and GaN (gallium nitride)1.


Takahiro Okazawa, Hioki’s President, says:

"We at HIOKI are determined to contribute to the safe and efficient use of energy by our customers through electric measurement, and to contribute to the peace of mind and development of society. Through new measurement solutions based on the Power Analyzer PW8001 and AC/DC Current Sensors CT6872 and CT6873, we will contribute to the realization of a sustainable society together with our customers worldwide."

Power Analyzer PW8001

Power Analyzer PW8001

Power Analyzer PW8001

AC/DC Current Sensors CT6872 and CT6873

Background of Development

In order to prevent global warming and ensure our next generation can flourish in earth’s precious natural environment, efforts are being made around the world to realize a carbon-free society. One of these efforts is the electrification of automobiles. Fervent research and development in electrification and performance improvement is accelerating on a global scale. Efficiency and miniaturization of motors and power supplies which is key in this research, is furthering demands for sophisticated measurement of materials, parts, and electric control. Measurement instruments now require more precise and stable measurements of DC (0 Hz frequency) to high frequency currents, large currents, and low power factor At the same time, devices being measured are increasingly complex and require multiple channels.

Meanwhile, when we look at energy generation, development related in renewable energy such as wind power and solar power is also accelerating worldwide. In order to make these renewable energies worthwhile, greater energy efficiency and lower costs for generation become important. For this, the development of related equipment to be higher voltage, lower cost, and higher productivity is on the rise. In this environment, measuring instruments are required to measure high voltages and multiples channels with high accuracy while being low cost.

We have developed the Power Analyzer PW8001 and Current Sensors CT6872 and CT6873 to meet the growing demands for measurement in these backgrounds.

Features of the PW8001


1. Custom Power Analyzer through 2-tiered Modules: World Class Accuracy, Wideband Power Measurement, and High Voltage Measurement

In order to attain world class accuracy, accuracy of DC (direct current) of 0 Hz frequency, commercial power accuracy (wall outlet) of 50/60 Hz frequencies and accuracy of higher frequencies must all be high. This is because most devices run on many frequencies. However, most power measurement devices focus on accuracy of either DC or the commercial frequencies (50/60 Hz). The PW8001 (module U7005*2) however achieves world class basic power accuracy of ±0.03% for commercial (50/60 Hz), and a DC (0 Hz) power accuracy of ±0.05% to provide more accuracy than other standard power analyzers in the market. In addition, this flagship model offers greater accuracy than competitors in measuring high-frequency power. The 5 MHz measurement bandwidth (increased from the previous model’s 2 MHz) is more important for SiC and GaN, the next-generation semiconductors increasing in use worldwide. The high accuracy in this overall wide frequency range makes it possible for users to accurately evaluate power conversion efficiency (or loss) of even more than 99% for power electronics equipment. In today’s technology where equipment are becoming more efficient and high-frequency, Hioki-level accuracy is essential to further improve performance.

Furthermore, this power analyzer gives the choice of two input modules with different measurement accuracy and measurement frequency bandwidth specs. Up to 8 input modules of the user’s choice (U7005 or U7001) can be freely combined into a single PW8001. The high-end module, U7005 (with aforementioned accuracy specs) and the more affordable module U7001 (basic power accuracy of ±0.07% and DC power accuracy of ±0.07% for commercial frequencies) allow for the optimum measuring system best suited for the user’s situation. Although the U7001 is marketed as the “affordable model,” its accuracy is nearly equivalent to that of the market-leading predecessor.

In addition, the new “affordable model” (U7001) allows for high voltage measurement of DC power. Rated at “DC 1500 V Category II” (CAT II), it can safely and accurately evaluate power supply equipment with a 1500 V DC voltage.


2. High Flexibility from a Revolutionary 8 channels and a Wide Array of Functions

The Power Analyzer allows the user to further tailor the analyzer to his/her specific application through its revolutionary number of 8 channels and many optional functions.

By providing a revolutionary number of 8 channels, Hioki’s single Power Analyzer can measure power efficiency of 2 independent 3-phase inverters, by comparing the power of each inverter’s single DC line and 3 AC lines. Comparable competitors only provide up to 7 channels, making this impossible without Hioki.

In addition to the standard 8 of 2-tiered modules, we have also prepared a function that can analyze four motors with just one Power Analyzer PW8001 by simultaneously measuring four sets of torque and rotation speed. This is very useful for evaluating complex systems such as in-wheel motors or electric AWD (all-wheel drive) systems installed in EVs in which individual wheels are controlled by several motors. (This Motor Analysis input is an optional function that must be specified when ordering.)

Another function that adds flexibility is the Optical Link Interface2 function. In order to respond to the increasing scale and complexity of power measurement, we have made it possible to measure up to 16 channels by connecting two PW8001s with optical cables. By combining two units, measured data is aggregated into one of the PW8001s in real time. This enables display, analysis, and recording for all 16 channels to be done on one device. (The Optical Link Interface*2, is an optional function that must be specified when ordering.)



Image of Optical Link Interface Function


3. High Accuracy Made Easy with the New Current Sensor Interface

High frequency power measurements are notorious for poor accuracy due to the higher alternating frequency of the electricity which causes current sensor’s accuracy to decline. However, Hioki’s unparalleled Phase Shift function can use Hioki’s fine-tuned current sensors to offset this phenomena. This is made possible only because Hioki makes both its power analyzers and sensors in-house, making giving Hioki a unique place in the market. This function makes efficiency measurement of inverters and loss measurement of high frequency reactors and transformers perfect for Hioki’s Power Analyzer. Until now, Hioki sensors simply required input of the sensor model’s phase error digits. The new current sensor interface in the Power Analyzer PW8001 and new sensors now make Phase Shifting incredibly easy. The Analyzer simply adjusting everything automatically as soon as the sensor is plugged in. This maximizes the performance of the current sensor without the need for tedious settings when preparing for measurement.



Image of New Current Sensor Interface


4. Streamline Automotive Development by Outputting Measurement Data as a CAN/CAN-FD Automotive Control Signal

In systems used in developing vehicles, the in-vehicle communication protocol of CAN or CAN-FD is widely used to aggregate data. Until now, CAN/CAN-FD signals and power analyzers’ analog output signals were collected simultaneously, then later all data were integrated into a data logger. However, analog output signals pose problems such as repeatability degradation at the time of integration and limited number of outputs. To solve these problems, the PW8001 offers an optional function that outputs the measured power data as a CAN signal. This allows data to integrate many channels without degradation of power measurement accuracy for simultaneous evaluation of many behaviors of a vehicle. (This CAN/CAN-FD Interface*2 is an optional function that must specified when ordering.)

Features of the Sensors CT6872 and CT6873


1. Next-Generation Semiconductors Power Evaluation

Next-generation semiconductor power inverters, such as SiCs and GaNs, often convert power into extremely high frequencies, too high for accurate measurement by non-Hioki sensors. The Hioki Current Sensors CT6872 and CT6873 are able to measure these frequencies very accurately with frequency bandwidths of up to 10 MHz and 5 MHz, respectively (a surprising 10-times increase from their previous models). In addition, these sensors are more accurate than their predecessor models with market leading accuracy by improving their amplitude/current accuracy and noise resistance (Common Mode Noise Rejection Ratio). These Hioki Current Sensors with such dramatically advanced performance, combined with the Power Analyzer PW8001’s excellent high-frequency accuracy, enables accurate and highly reproducible power supply evaluations even in the high-speed switching power supplies equipped with next-generation semiconductors such as SiCs and GaNs.

Video: PW8001 – Complete Power Analysis


Main Applications/Customers

■  Evaluation of power conversion efficiency and loss in research & development and production processes

■  Manufacturers of EVs, FCVs (fuel cell vehicles), other automobiles, and their chargers

■  Manufacturers of equipment for renewable energy generation such as wind and solar

Dedicated Website for These Products

(English) https://www.hioki.com.sg/power-analyzer-pw8001-introduction

(Japanese) https://lpcreator.hioki.co.jp/pw8001_top_jp


For more product information, please click on the links below:

Power Analyzer PW8001 Brochure

PW8001 – Complete Power Analysis (video)

Evaluation of Dual-Inverter Drive System Performance with Power Analyzer PW8001

Evaluation of Solar Inverter Based Power Interchange Systems with Power Analyzer PW8001

1 SiC and GaN are new, low-loss, high-voltage, power semiconductors suitable for high-temperature operation. Their use in high-performance power supply equipment is expanding because these semiconductors’ characteristics allow for smaller passive electronic components and cooling devices.

2 Scheduled to be released in 2022.

26 July 2021 : What is Harmonics and How to Identify the Harmonics Sources in your Facility with HIOKI PQ3198?

What is Harmonics and How to Identify the Harmonics Sources in your Facility with HIOKI PQ3198?

What is Harmonics and How is it Generated?

In an ideal AC circuit with a sinusoidal voltage waveform, the corresponding current through the linear resistor will also be in sinusoidal waveform [1]. This waveform is called the fundamental waveform (or 1st order harmonics) and corresponds to the single supply frequency called the fundamental frequency, which is the lowest frequency. 

However as most electrical loads have non-linear voltage-current characteristics [2] (current is not proportional to voltage and fluctuates with the alternating load impedance), the resulting sinusoidal wave will have a frequency that is an integer multiple of the fundamental frequency. If the frequency is n multiples of the fundamental frequency, it is the nth order harmonics of the fundamental frequency. For a 50 Hz voltage, the 2nd order harmonics frequency is 2×50 = 100 Hz, 3rd order harmonics frequency is 3×50 = 150 Hz, and so on.

The superimposition of these multiple frequency waveforms with the fundamental frequency will result in a distorted non-sinusoidal waveform called harmonics. Figure 1.0 below illustrates the concept of voltage harmonics for a 50 Hz fundamental frequency voltage.


Figure 1.0 Voltage Harmonics Waveform for a 50 Hz Fundamental Frequency Voltage

Common Sources of Harmonics

Non-linear loads are common sources of harmonics in power systems, where the current is not proportional to the voltage [3]. Examples of non-linear loads are:

IT Equipment Power Supply Unit (PSU) component (to convert from AC to DC)


Lighting with Power Factor Correction (PFC) Circuit (to increase energy efficiency)


Variable Frequency Drive (VFD) and Variable Speed Drive (VSD) (to control motor speed)


Effects of Harmonics

Table 1.0 below lists examples of the effects of harmonics on various equipment. 




Overheating, nuisance tripping (MCCB)


Heating, premature aging and destruction of capacitor

Transformers and Motors

Overheating of the windings, thermal insulation loss, reduced efficiency

Power Generators

Loss in automatic synchronization and switching capability

Communication System Equipment

Interference leading to loss in data

Table 1.0 Harmonics Effect on Various Equipment

Source: https://www.electricalindia.in/harmonics-causes-effect/


Generally, harmonics reduce the overall electrical system’s Power Factor (PF), which is represented by the ratio of real power (usable electricity) to apparent power (demand power). A PF that is lower than 1 indicates low power efficiency.


Harmonics Measurement

Harmonics are measured in terms of Total Harmonic Distortion (THD) and Total Demand Distortion (TDD). Table 2.0 compares both parameters from different aspects.





Parameter Indiction

Percentage of voltage/current distortion due to harmonics with reference to fundamental frequency [4]

Percentage of voltage/current distortion due to harmonics with reference to maximum load demand [4]


Ratio of Sum of powers of all harmonics component to Power of Fundamental Frequency

Ratio of Sum of powers of all harmonics component to Power of Maximum Load Demand

Value Indication

Higher value indicates lower Power Factor, higher current peaks, higher cost [5]

Higher value indicates higher impact of harmonics distortion on the system

Limit Standard

IEC 61000-3-2

IEEE 519

Table 2.0 THD and TDD comparison


For current, the TDD current gives a better insight into the impact of harmonics distortion on the power system e.g. the THD current value might be very high but if the load is low, the impact of the harmonics on the system is also low (low TDD). For voltage, however, the THD index is the preferred parameter to describe voltage harmonics distortion by the power quality industry [7].


HIOKI PQ3198 for Harmonics Measurement and Source Identification

The Hioki PQ3198 is equipped with a simple vector diagram display that helps to ensure correct connection for harmonics measurement. This colour-coded ‘needle-and-box’ display shows both voltage and current measurements. A correct connection is denoted by the same colour in the needle and box, as shown below in Figure 2.0. 


Figure 2.0 Vector Diagram Display on PQ3198 for Connection


The PQ3198 can also determine the harmonics measurement load type (inductive or capacitive load) using the Power Factor (PF) sign, shown in Figure 3.0 below.


Figure 3.0 Power Factor Value Display on PQ3198 to determine type of load


Inductive load, indicated by a positive (+) PF value, causes the current rate to be blocked. Thus, the current wave shifts horizontally and lags behind the voltage wave. Inductive loads mainly consist of devices with wire coils or function based on the Magnetic Induction Principle (Figure 4.0); inductive loads consume active power and produce reactive power. [8]  


Figure 4.0 Examples of Inductive Loads


Capacitive load is indicated by a negative (-) PF value, with the current wave leading the voltage wave instead. Capacitive loads consist of any electrical device that can absorb electrical energy in a moment (capacitance) (Figure 5.0).


Figure 5.0 Examples of Capacitive Loads


Users can also determine the direction of harmonics flow based on the harmonics power sign and harmonics phase angle values. Figure 6.0 shows an example of measurements for both parameters on the PQ3198, for 3rd order harmonics.


Figure 6.0 Harmonics Power (left) and Phase Angle (right) for a 3rd Order Harmonics


However, the harmonics power value decreases with higher harmonics orders, making it difficult to judge polarity. Hence, the harmonics power phase angle acts as a second parameter to determine the direction of flow (Figure 7.0).


Figure 7.0 Harmonics Power (left) and Phase Angle (right) for a 11th Order Harmonics


Table 3.0 summarizes the methods used to determine the direction of harmonics flow based on the harmonics power sign and phase angle values.





Harmonics Flow Direction

Distribution to Load

*Harmonics measured at Point of Common Coupling (PCC)

Load to Distribution

*Harmonics measured at Point of Common Coupling (PCC)

Harmonics Power Phase Angle Value

-90° to 0° OR 0° to 90°

-90° to -180° OR 90°to 180°

Harmonics Power Sign

Positive (+)

Negative (-)

Disclaimer: The flow direction should only be used as a reference and not a conclusive indication for the source of harmonics. For multiple harmonics, which is a vector made up of amplitude and phase, it is not easy to determine the source of harmonics based solely on flow direction as most power supply contains some form of harmonics. 

Table 3.0 Harmonics Power and Phase Angle to Determine Harmonics Flow Direction


The THD and the TDD values can be measured using PQ3198. These values can then be analyzed and displayed using the PQ One software (Figure 8.0).


Figure 8.0 THD and TDD Analysis using PQ One Software


There’s also an option to view the vector of harmonics in Linear and Logarithmic view, which is useful for viewing low phase angle vector values (Figure 9.0).


Linear Vector Display

Logarithmic Vector Display

Helps in viewing the phase angle more clearly for low phase angle vector values ( I2 in this case)

Figure 9.0 Vector View of Harmonics in Linear (left) and Logarithmic (right)


The PQ3198 is also capable of capturing high-order harmonics waveform up to 80 kHz (this is mostly generated by electronic components in Power Supply Unit (PSU) installed in semiconductor devices) (Figure 10.0).


Figure 10.0 Screenshot of a High Order Harmonics Waveform


Other key features of the PQ3198 for harmonics measurement include:

    • Compliance with IEC 61000-4-30 Ed. 3 Class A standard
    • Auto-recovery mode from power source depletion where the PQ3198 will automatically restart and start recording when the AC power source resumes, ensuring continuous data logging



    • Built-in HTTP server function which allows user to check the results and configure the PQ3198 using a browser
    • Built-in FTP function which allows user to retrieve the data at any time and place
    • Integrate with GENNECT One freeware for multiple devices (maximum of 15 instruments) logging of up to 512 parameters and also stand-alone BMS function
    • Synchronization to the UTC Standard time by using Hioki PW9005 GPS Box (useful for multiple PQ3198 data comparison)



Since harmonics is a measurable parameter, it can also be controlled using several basic methods [9]:

    • Reducing harmonics currents in loads i.e. by adding a line reactor or transformer in series
    • Adding filters to siphon or block the harmonic currents from the system i.e. shunt filters which work to short-circuit harmonics currents as close as possible to the source and active filters that electronically supply the harmonic component of the current into a non-linear load 
    • Modifying the frequency responses of the system to harmonics i.e. changing capacitor size, moving or removing capacitor, and adding a reactor to detune the system


In conclusion, harmonics measurement is crucial as it impacts the power efficiency, functionality and lifespan of equipment; the source(s) of harmonics need to be identified and controlled before it brings harm to the equipment. The PQ3198 is equipped with multiple features that enable correct and meaningful harmonics measurement and source identification. 


For more product information, please click on the links below:

Hioki Power Quality Analyzer PQ3198

Hioki Power Quality Analyzer Catalogue

How to Select The Right Power Quality Analyzer and Power Logger



1. https://www.electronics-tutorials.ws/accircuits/harmonics.html

2. https://www.riello-ups.co.uk/questions/39-what-s-the-difference-between-linear-and-non-linear-loads

3. https://www.mtecorp.com/blog/2018/04/09/effects-of-harmonics-in-power-system/

4. http://www.elnet.cc/thd-and-tdd/

5. https://www.allaboutcircuits.com/technical-articles/the-importance-of-total-harmonic-distortion/


7. https://www.ecmweb.com/design/article/20890327/understanding-harmonic-indices

8. https://diary-of-electric.blogspot.com/2020/02/explanations-about-resistive-inductive-and-capacitive-loads.html

9. https://electrical-engineering-portal.com/principles-for-controlling-harmonics


29 Jun 2021 : HIOKI Clamp On Power Logger PW3360: for Electrical Load Study

HIOKI Clamp On Power Logger PW3360: For Electrical Load Study


What is Electrical Load Study?

An electrical load is a part of a circuit that consumes electricity and is a direct
measure of power output [1]. Electrical loads can be components that convert
electricity to light, heat, or mechanical motion (Figure 1.0). Hence, an electrical load study is a study to determine the actual electrical panel energy usage [2] for all electricity-consuming items. In this study, the active and reactive power, voltage, current, and power factor throughout the entire system is determined [3]. An electrical load study is done to ensure that the existing panel can supply the power drawn for loads usage and is particularly critical when a new load is introduced, such as in the event of space expansions and renovations to existing buildings.


Figure 1.0 Example of electrical load


The importance of electrical load study

Any expansions or renovations to the existing building that adds new load to the system could result in electrical circuit overload, where the current drawn exceeds its rated load and therefore compromise the safety of the system. Signs of overloaded circuits include [4]:

• Tripped circuit breakers
• Dimming or flickering lights when loads are turned on
• Buzzing outlets or switches
• Warm to the touch outlets or switch covers during load operation
• Scorched plugs or outlets
• Burnt smell during load operation

Circuit breakers are the first line of defense to protect the system from overload incidents. Existing circuit breakers might not be functioning sufficiently when new load are introduce to enable safe operations, which could result in fire hazard.


Figure 2.0 IEC standard for overload protection current by protective relay type


How is an electrical load study done?

An electrical load study is done by monitoring the electrical power used over a period using a power logger. According to the following clause[5] from IEC 60364-8-1 standard for Low Voltage Electrical Installations, the interval required for the monitoring for the load study is as follow:

As there’s no specific time interval mentioned, the recording interval should be set based on the recording duration required to enable a meaningful and representative view of the power consumption for the load study.

Hioki Power Logger PW3360 for Electrical load study

Hioki’s Clamp On Power Logger PW3360 enables easy and error-proofed electrical load measurement. The QUICK SET function in PW3360 helps users to avoid some mistakes commonly made during electrical load study using a power logger such as the following:

1. Wrong wire clamping from logger to conductor line resulting in incorrect power measurement
2. Reverse direction of clamp sensor from the load (the arrow on the current probe should point to the load direction), which leads to a negative value of power data
3. Incorrect range setting resulting in inaccurate measurements



Figure 3.0 shows the screen view of the QUICK SET function on PW3360 and how the above three mistakes can be avoided with this feature.


Figure 3.0 Screen view of QUICK SET function on PW3360

Other key features include:

• 1P2W, 3P3W, and 3P4W measurement capability with three channels for current measurement
• Single 600V range with effective guaranteed accurate measurement up to 780V and view display up to 1000V
• Load current measurement range of 500mA to 5000A
• Power measurement range of 300.00 W to 9.0000 MW
• Continuous measurement with no gap (critical for power profile measurement)

Figure 4.0 Continuous measurement with no gap


•Built-in HTTP and FTP server function that allows users to configure and monitor the instrument from a browser as well as download the data. Multiple PW3360 (up to 4 units) can be paired with Hioki’s LR8450 Memory HiLogger during power load study and result viewed in real-time via GENNECT One free software

Figure 6.0 Multiple PW3360 (up to 4 units) can be paired with Hioki’s LR8450 Memory HiLogger during power load study and result viewed in real-time via GENNECT One free software


•Storage to 2GB SD Card
The maximum recording duration depends largely on the interval setting for the load study. Table 1.0 below list the interval settings and their corresponding maximum recording duration.

Table 1.0 Maximum recording duration by interval setting time

For Power Demand logging, a 30 minutes interval setting is recommended as the electricity revenue meter is also based on this interval length.
The Power Demand trend (Figure 7.0) from data logging enables users to:

• View the power demand transitions according to the recording interval setting. Users can view the Active Power Demand (Pdem+) as well as Reactive Power Demand (Qdem+)
• Use the data for power consumption management

Figure 7.0 Power Demand graph display on PW3360

There’s also the Power Trend graph (Figure 8.0) whereby users can:

• Scroll through point-by-point measured interval
• View each interval’s maximum, minimum and average power consumption
• Use this interval data to identify changes due to the operating condition of machinery or equipment on-site

Figure 8.0 Power Trend graph display on PW3360


The voltage, current, power, and energy can be viewed as a list (Figure 9.0) as well as in detail (voltage and current) (Figure 10.0)

Note: For electricity consumption, the FUNDAMENTAL WAVE calculation is used when measuring power factor DPF (displacement power factor) and reactive power Q and also apparent power S.

Figure 9.0 voltage, current, power, and energy can be viewed together on PW3360 screen

Figure 10.0 Voltage and current view in detail


Hioki’s Clamp On Power Logger PW3360 features give users the confidence to execute power load study correctly whilst collecting representative power consumption data.


For more product information, please click on the links below:

Hioki Clamp On Power Logger PW3360

Hioki Clamp On Power Logger PW3360 Catalogue

How to Select The Right Power Quality Analyzer and Power Logger