Clamp Meters

Products
How To Use The Product
Types of Clamp Meters

AC/DC Clamp Meters

Clamp meter | CM4375

AC/DC CLAMP METER   CM4375

Easily get into tight spaces
1000 A AC/DC range

Clamp meter | CM4375

• Easily get into tight spaces • 1000 A AC/DC range • V, A, Hz, Ω, and other extensive measurement parameters

Clamp meter | CM4376

AC/DC CLAMP METER   CM4376

Easily get into tight spaces
1000 A AC/DC range

Clamp meter | CM4376

• Easily get into tight spaces • 1000 A AC/DC range • V, A, Hz, Ω, and other extensive measurement parameters • Built-in Bluetooth (R) wireless technology

DISPLAY UNIT CM7291

DISPLAY UNIT   CM7291

Power supply / signal output
for Current Sensor CT7000 series

DISPLAY UNIT CM7291

• Built in Bluetooth®wireless technology • Use with CT7000 series • DCA, ACA, (DC+AC)A, frequency • WAVE, RMS, PEAK, Hz output

True RMS 2000 A AC/DC Clamp Meter with Bluetooth | CM4374

AC/DC CLAMP METER   CM4374

Rugged AC/DC Clamp
for the Toughest Situations

True RMS 2000 A AC/DC Clamp Meter with Bluetooth | CM4374  

• 600/2000 A range • V, A, Hz, Ω, and other extensive measurement parameters • Inrush current • Built-in Bluetooth® wireless technology

True RMS 600 A AC/DC Clamp Meter with Bluetooth | CM4372

AC/DC CLAMP METER   CM4372

Rugged AC/DC Clamp
for the Toughest Situations

True RMS 600 A AC/DC Clamp Meter with Bluetooth | CM4372  

• 20/600 A range • V, A, Hz, Ω, and other extensive measurement parameters • Inrush current • Built-in Bluetooth® wireless technology

DISPLAY UNIT CM7290

DISPLAY UNIT   CM7290

Power supply / signal output
for Current Sensor CT7000 series

DISPLAY UNIT CM7290  

• Use with CT7000 series • DCA, ACA, (DC+AC)A, frequency • WAVE, RMS, PEAK, Hz output

True RMS 600 A AC/DC Clamp Meter | CM4371

AC/DC CLAMP METER   CM4371

Rugged AC/DC Clamp
for the Toughest Situations

True RMS 600 A AC/DC Clamp Meter | CM4371  

• 20/600 A range • V,A,Hz,Ω or other, extensive measurable parameters • Inrush current

True RMS 2000 A AC/DC Clamp Meter | CM4373

AC/DC CLAMP METER   CM4373

Rugged AC/DC Clamp
for the Toughest Situations

True RMS 2000 A AC/DC Clamp Meter | CM4373  

• 600/2000 A range • V,A,Hz,Ω or other, extensive measurable parameters • Inrush current

Wireless Clamp Logger LR8513

WIRELESS CLAMP LOGGER   LR8513

For AC/DC current recording
Fastest 0.5 sec interval

Wireless Clamp Logger LR8513

• For AC/DC current recording • Fastest 0.5 sec interval • Wireless data download to a tablet or computer

AC/DC Clamp Meter | Clamp On AC/DC HiTester 3287

CLAMP ON AC/DC HiTESTER   3287

10A/100A AC/DC Clamp Meter with Continuity Check and Resistance Testing Capabilities

AC/DC Clamp Meter | Clamp On AC/DC HiTester 3287

• For AC/DC measurement • True RMS • 10/ 100 A range • Light weight 170 g, 16 mm thin body • DMM function

AC/DC Clamp Meter | Clamp On AC/DC HiTester 3288, 3288-20

CLAMP ON AC/DC HiTESTER   3288

100A/1000A AC/DC Clamp Meters with Continuity Check and Resistance Testing Capabilities

AC/DC Clamp Meter | Clamp On AC/DC HiTester 3288, 3288-20

• For AC/DC measurement • True RMS (3288-20) • Average rectified (3288) • 100/ 1000 A range • Light weight 150 g, 16 mm thin body • DMM function

AC/DC Clamp Meter | Clamp On AC/DC HiTester 3284

CLAMP ON AC/DC HiTESTER   3284

20A/200A AC/DC Clamp Meters with Analog Output and Peak Hold for Inrush Measurement Applications

AC/DC Clamp Meter | Clamp On AC/DC HiTester 3284

• For AC/DC measurement • True RMS • 20/ 200 A range • DC/ AC/ AC+DC mode • Peak value at inrush current

AC/DC Clamp Meter | Clamp On AC/DC HiTester 3285

CLAMP ON AC/DC HiTESTER   3285

200A/2000A AC/DC Clamp Meters with Continuity Check and Resistance Testing or Analog Output

AC/DC Clamp Meter | Clamp On AC/DC HiTester 3285

• For AC/DC measurement • True RMS • 200/ 2000 A range • DC/ AC/ AC+DC mode • Peak value at inrush current

 

AC Clamp Meters

AC Clamp Meter | CM3289

AC CLAMP METER   CM3289

42 to 1000 A AC range
100 g/16 mm

AC Clamp Meter | CM3289

• Get into even more confined spaces • 42 to 1000 A AC range • DMM function

AC Clamp Meter | 3280-10F

AC CLAMP METER   3280-10F

42 to 1000 A AC range
100 g/16 mm

AC Clamp Meter | 3280-10F

• 42 to 1000 A AC range • Weighing only 100g with thin 16 mm body • DMM function

Data Logger | Clamp Logger LR5051

CLAMP LOGGER   LR5051

2 ch, AC current recording
1 sec logging interval

Data Logger | Clamp Logger LR5051

• 2ch • AC current recording • 1 sec logging interval

AC Current | Clamp Meter 3281

DIGITAL CLAMP ON HiTESTER   3281

30 to 600 A AC range
Wave peak value at inrush current

AC Current | Clamp Meter 3281

• 30 to 600 A AC range • Wave peak value at inrush current • Waveform distortion check

AC Current | Clamp Meter 3282

DIGITAL CLAMP ON HiTESTER   3282

30 to 1000 A AC range
Wave peak value at inrush current

AC Current | Clamp Meter 3282

• 30 to 1000 A AC range • Wave peak value at inrush current • Waveform distortion check

 

AC Current Measurement Options

AC Current Transformer (CT) for Clamp Meters | 9290-10

CLAMP ON ADAPTER   9290-10

AC Current Transformer to Meet Applications Exceeding 1000A AC

AC Current Transformer (CT) for Clamp Meters | 9290-10

• Primary 1000A, secondary 100A (1/10 ratio) output • Superior phase angle characteristics for power

 

Leakage Current Clamp Meters

Wireless Clamp Logger LR8513

WIRELESS CLAMP LOGGER   LR8513

For AC/DC current recording
Fastest 0.5 sec interval

Wireless Clamp Logger LR8513

• For AC/DC current recording • Fastest 0.5 sec interval • Wireless data download to a tablet or computer

Clamp-On Ground Resistance Tester | FT6380

CLAMP ON EARTH TESTER   FT6380

Easy Pole Clamp-On Ground Resistance Tester with Super Slim Jaw

Clamp-On Ground Resistance Tester | FT6380

• Earth resistance measurements for multi-grounded systems • Leak to load current • True RMS

Clamp-On Ground Resistance Tester | FT6381 | Bluetooth® Wireless Technology

CLAMP ON EARTH TESTER   FT6381

Lightweight Ground Resistance Tester with Bluetooth® Data Transfer

Clamp-On Ground Resistance Tester | FT6381 | Bluetooth® Wireless Technology

• Earth resistance measurements for multi-grounded systems • Leak to load current • True RMS • Automatic measurement report function with Android™ connectivity (FT6381 only)

Data Logger | Clamp Logger LR5051

CLAMP LOGGER   LR5051

2 ch, AC current recording
1 sec logging interval

Data Logger | Clamp Logger LR5051

• 2ch • AC current recording • 1 sec logging interval

Leakage Current Clamp Meter | Clamp On Leak HiTester 3293-50

CLAMP ON LEAK HiTESTER   3293-50

1mA to 1000A AC Leakage to Load Current Clamp Meter with 10 µA Resolution in Innovative Flip Design

Leakage Current Clamp Meter | Clamp On Leak HiTester 3293-50

• True RMS • 30 mA leak current range with 10 µA resolution • 1000 A max. load current

Leakage Current Clamp Meter | Clamp On Leak HiTester 3283

CLAMP ON LEAK HiTESTER   3283

1mA to 200A AC Leakage Current Clamp Meter with 10 µA Resolution to Analyze Distorted Waveforms

Leakage Current Clamp Meter | Clamp On Leak HiTester 3283

• True RMS • AC leak current and load current testing • 10 mA leak current range with 10 µA resolution • Load current up to 200 A

 

Clamp Power Meters

Handheld Power Meter | CM3286

AC CLAMP POWER METER   CM3286

Measures from 5 W of power, 60 mA of current
simple integral power consumption and phase sequence

Handheld Power Meter | CM3286

• Easy AC power checker • Single-phase, 3-phase (balanced condition/without distortion) • Phase angle, power factor

 

Connecting instruments in the field with IT

GENNECT CROSS SF4071, SF4072

GENNECT CROSS   SF4071, SF4072

Free mobile and PC app
Available for Android and iOS

GENNECT CROSS SF4071, SF4072

• Streamline tasks that require repeated measurement and recording of values • Available for Android and iOS

 

01. How to use clamp meters

How to use load current clamp meters

When measuring load current in a 1-phase 2-wire circuit as shown in the figure, the clamp meter should be applied around one (not both) of the wires.

Because the current flowing to and from the load in the two wires forms a pair of magnetic fields that are opposite one another, the two magnetic fields cancel each other out, causing the clamp meter to indicate a current value of zero if two wires are measured at the same time.

When measuring a 3-phase circuit, it is necessary to measure the current value in each of the R, S, and T wires by applying the clamp meter to each in turn.

  

How to use leakage current clamp meters

When measuring leakage current in a 1-phase/2-wire circuit as shown in the figure, the clamp meter should be applied around both wires.

Because the current flowing to and from the load in the two wires forms a pair of magnetic fields that are opposite one another, there will be a difference in the two fields if there is any leakage current. The measured current value when the clamp meter is applied around both wires at the same time is the leakage current.

When measuring a 3-phase circuit, the clamp meter should be applied around the R, S, and T wires (all three wires) at once. Leakage current can also be measured by applying the clamp meter around a grounding wire.

02. Clamp meter functions and how to use them

Current measurement

•    Set the rotary switch as shown in “1”.
•    Enable zero-adjustment as shown in “2”.
•    Apply the clamp meter around the wire as shown in “3”.
•    Determine the function as appropriate from auto, AC current, DC current, AC+DC current, or frequency as shown in “4”.

*This example uses the Clamp Meter CM4370 series.  

HOLD function

MANUAL HOLD:
•    The measured value on the display can be held by pressing the HOLD key.

AUTO HOLD:
•    Press and hold the HOLD key for 1 sec. to enable the auto hold function.
•    Once the measured value stabilizes, it will be automatically held as shown in the figure.
•    The measured value will continue to be held once the clamp is removed from the wire.
•    Once you apply the clamp meter around another wire and the measured value stabilizes, it will be automatically held again.
•    This function is convenient when you need to make and record results for a series of measurements.

*This example uses the Clamp Meter CM4370 series.
 

Filter function

•    The filter can be applied based on a 100 Hz cutoff frequency.
•    This function is convenient when you wish to measure the current value near the power supply frequency without being affected by noise or other interference.

*This example uses the Clamp Meter CM4370 series.

MAX/MIN/AVG/PEAK

•    The MAX/MIN/AVG function records the maximum, minimum, and average values for the measured value (RMS) interval being displayed.
•    The peak max and peak min functions display the maximum and minimum values of current waveform peaks after 10 kHz sampling.

*This example uses the Clamp Meter CM4370 series.  

DC current and DC voltage PEAK measurement

•    Apply the clamp around the wire coming from the vehicle battery’s positive terminal as shown in “1” in the figure and set the rotary switch as shown in the figure.
•    Operate the control key as shown in “2” in the figure.
•    Start the vehicle’s engine.
•    By performing the steps shown in “4” in the figure, you can read the maximum and minimum values for the instantaneous DC current when the engine is started as well as the DC voltage maximum and minimum values.

*This example uses the Clamp Meter CM4370 series.   

Inrush current measurement (INRUSH)

•    Disconnect the power supply of the motor or other load.
•    Determine the appropriate position for the rotary switch as shown in “2” in the figure.
•    Perform zero-adjustment as shown in “3” in the figure.
•    Apply the clamp around one of the load circuit’s wires as shown in “4” in the figure.
•    Enable the INRUSH function as shown in “5” in the figure.
•    Start the motor or other load.
•    As shown in “7” in the figure, you can read the peak (maximum peak value) and RMS value for the interval during which the inrush current (starting current) occurs.

*This example uses the Clamp Meter CM4370 series.

Other measurement functions: Voltage measurement

•    Connect the measurement leads to the clamp meter.
•    Set the rotary switch to voltage measurement as shown in “1” in the figure.
•    Place the measurement leads in contact with the point you wish to measure as shown in “2” in the figure.
•    Select the desired function (auto, AC voltage, DC voltage, AC+DC voltage, or frequency) as shown in “3” in the figure.

*This example uses the Clamp Meter CM4370 series.

  

Other measurement functions: Continuity check, Resistance, Diode

•    Set the rotary switch to the position shown in the figure.
•    Using the SHIFT key, you can check continuity or perform resistance or diode measurement.

*This example uses the Clamp Meter CM4370 series.  

Other measurement functions: Capacitance, Temperature

•    After setting the rotary switch to TEMP, you can use the SHIFT key to perform capacitance or temperature measurement.

*This example uses the Clamp Meter CM4370 series.

Other measurement functions: Electric charge detection, Simultaneous display of DC current and voltage, DC power

After determining the rotary switch position as shown in the figure, you can use the SHIFT key to detect a voltage, simultaneously display DC current and voltage, or measure the DC power being produced by a solar power system.

*This example uses the Clamp Meter CM4370 series.   

03. Clamp meter measurement principles

Clamp meter measurement principles: CT method

Clamp meters measure current by using a sensor to detect the magnetic field produced by a flowing current and then converting the result to obtain the current. The measurement method and principle used by CT-type clamp meters are described below.

Design:
Coil wound around a magnetic core

Principle:
In this application of the principle of a transformer, the primary side consists of one winding (the wire around which the clamp has been applied), and the second side consists of N windings (the wire wound around the magnetic core). This arrangement is used to measure current. Due to the principle that is applied, caution is necessary if a current flows to the primary side while the secondary side is in the open state as a high voltage may occur at the open terminal due to the tendency of a current to develop on the secondary side of the device under such conditions.

Advantages:
Linearity and broad measurement range

Disadvantages:
Inability to detect DC currents

  

Clamp meter measurement principles: Hall element method

Clamp meters measure current by using a sensor to detect the magnetic field produced by a flowing current and then converting the result to obtain the current. The measurement principle used in the Hall element method is described below.

Design:
Hall element embedded in a magnetic core

Principle:
The magnetic field produced by the wire around which the clamp has been applied is converted to a voltage by the Hall element, and the voltage is converted to a current.

Advantages:
Ability to measure both DC currents and AC currents

Disadvantages:
Significant impact of sensor enclosure, magnetic circuit, and magnetic core design on instrument performance  

Clamp meter measurement principles: Rogowski method

Clamp meters measure current by using a sensor to detect the magnetic field produced by a flowing current and then converting the result to obtain the current. The measurement principle used in Rogowski-type clamp meters is described below.

Design:
Rogowski coil wound around a coreless, nonmagnetic material

Principle:
Differentiated voltage waveforms are output at both ends of the coil depending on the current. The waveforms are integrated to calculate the current.

Advantages:
Flexibility due to the absence of a core, broad frequency band

Disadvantages:
Limited to measurement of AC currents

Types of clamp meters

There are two types of clamp meter: instruments designed to measure load current and instruments designed to measure leakage current. The former can be further subdivided as follows:

•    Models designed to measure AC current with frequency band characteristics that are centered on commercial power supply frequencies

•    Models designed to measure DC current as well as AC current at frequencies at and below commercial power supply frequencies from devices such as general-purpose inverters

Clamp meters can also be classified on the basis of the rectification method they use (either mean-value rectification or RMS rectification).

Rectification methods of clamp meters

There are two methods for converting current into true RMS values: the true RMS method (true RMS value indication) and the mean method (mean rectification RMS value indication).

Although both methods yield the same value for undistorted sine waves, distortion of the waveform causes the values to diverge.

Most current measurement applications involve measurement of a current waveform that is not a perfect sine wave (i.e., they require measuring a current waveform that is distorted). If you wish to view results in the form of true RMS values, it is recommended to use a true RMS clamp meter.