Product Introduction

This double clamp earth resistance meter is a portable non-stop testing instrument developed for on-site grounding detection. With integrated double-clamp sensing structure, it eliminates the need to excavate soil or lay auxiliary poles, greatly improving testing efficiency. Built with advanced signal processing algorithm, it effectively suppresses on-site industrial interference and delivers stable and accurate grounding resistance data. Compact body and long battery life make it ideal for daily maintenance and periodic inspection of various grounding networks.

Product Parameter (specification)

Function	Measurements of grounding resistance, soil resistivity, DC resistance, continuity resistance, equipotential bonding resistance, grounding voltage, AC current, and leakage current.
Power supply	DC 7.4V 1.8Ah rechargeable lithium battery
Backlight	Controllable backlight, suitable for use in dimly lit places.
Measurement method	Precision four-wire and three-wire methods for measuring grounding resistance, simplified two-wire method, selection method, and double-clamp method.
Measurement methods	Two-, three-, and four-wire method for measurement: pole changing method, short-circuit measurement current 20mA Max. Selection method measurement: Polarity changing method, short-circuit measurement current 20mA Max Dual-clamp method: Non-contact mutual inductance measurement method, test current 1mA max. Soil resistivity: Four-electrode method ( Winner method ) DC Resistance: Polarization Method Alternating current: Average value rectified (clamp-on) Voltage to ground: Average value rectified (between P(S) and ES interfaces)
Range	Two-, three-, and four-wire method for measuring grounding resistance (Re) and DC resistance: 0.00 Ω ～30.00kΩ
	Selective method for measuring grounding resistance (Re): 0.00Ω～3000Ω
	Dual-clamp method for measuring grounding resistance (Re): 0.01Ω～200Ω
	Soil resistivity (ρ): 0.00Ωm～9000kΩm
	Grounding voltage (50Hz/60Hz): AC 0.0～100.0V
	Alternating current (50Hz/60Hz): AC 0.00mA～600.0A
Resolution	Two-, three-, and four-wire method for measuring grounding resistance (Re) and DC resistance: 0.001Ω (0.000Ω～29.999Ω) 0.01Ω (30.00Ω～299.99Ω) 0.1Ω (300.0Ω～2999.9Ω) 1Ω (3.000kΩ～30.00kΩ)
	Selection method for measuring grounding resistance (Re): 0.01Ω (0.00Ω～29.99Ω) 0.1Ω (30.0Ω～299.9Ω) 1Ω (300Ω～3000Ω)
	Dual-clamp method for measuring grounding resistance (Re): 0.01Ω (0.01Ω～0.99Ω) 0.1Ω (1.0Ω～29.9Ω) 1Ω (30Ω～200Ω)
	Soil resistivity (ρ): 0.01Ωm (0.00Ωm～99.99Ωm) 0.1Ωm (100.0Ωm～999.9Ωm) 1Ωm (1000Ωm～9999Ωm) 10Ωm(10.00kΩm～99.99kΩm) 100Ωm (100.0kΩm～999.9kΩm) 1kΩm (1000kΩm～9000kΩm)
	Grounding voltage (50Hz/60Hz): 0.1V
	Alternating current (50Hz/60Hz): 0.01mA
Accuracy accuracy	Two-, three-, and four-wire method for measuring grounding resistance (Re) and DC resistance (R-): ±2%rdg±5dgt (0.000Ω～29.999Ω) ±2%rdg±3dgt (30.00Ω～299.99Ω) ±2%rdg±3dgt (300.0Ω～2999.9Ω) ±4%rdg±3dgt (3.000kΩ～30.00kΩ) Note: 1. Additional error at rC max or rP max ≤ ±5%rdg±5dgt. (rC max: 4kΩ+100R＜50kΩ, rP max: 4kΩ+100R＜50kΩ) 2. Additional error at 5V interference voltage ≤ ±5%rdg±5dgt.
	Selection method for measuring grounding resistance (Re): ±2%rdg±5dgt (0.00Ω～29.99Ω) ±2%rdg±3dgt(30.0Ω～299.9Ω) ±2%rdg±3dgt (300Ω～3000Ω)
	Dual-clamp method for measuring grounding resistance (Re): ±10%rdg±5dgt (0.01Ω～100Ω) ±20%rdg±5dgt(101Ω～200Ω)
	Soil resistivity (ρ): Depends on the measurement accuracy of R. (ρ=2πaR a:1 m～100m; π=3.14)
	Grounding voltage (50Hz/60Hz): ±2%rdg±3dgt
	Alternating current (50Hz/60Hz): ±2%rdg±3dgt
Test voltage waveform	sine wave
Test frequency	128Hz/111Hz/105Hz/94Hz (Auto Frequency Selection)
Short-circuit test current	AC 20mA max
Open circuit test voltage	AC 40V max
Electrode spacing range	1m～100m
Display mode	6-digit extra-large LCD display with backlight
Measurement indication	During measurement, the LED flashes to indicate the time and the LCD displays a countdown.
LCD size	128mm×75mm
LCD display area	124mm×67mm
Equipment size	Instrument dimensions (length × width × height): approximately 320 mm × 275 mm × 145 mm Current clamp dimensions: approximately 220mm × 100mm × 27mm
Packaging size	Outer packaging dimensions: approximately 400mm × 245mm × 335mm
Test line	One each of red (20m), black (20m), yellow (10m), and green (10m).
Simple test line	Two strips: one red 1.6m strip and one black 1.6m strip.
Auxiliary grounding rod	4 pieces: φ10mm×150mm
Current clamp	Two sets: One pair of clamp A (blue and black plug), and one pair of clamp B (red and black plug).
Current clamp diameter	φ 52 mm
Current clamping ratio	1000:1
Current clamp leads	2m long
Measurement time	Alternating current: approximately 2 times/second Voltage to ground: approximately 2 times/second Grounding resistance: approximately 7 seconds/time
Number of measurements	More than 5000 short-circuit tests (test once, pause for 30 seconds, then test again).
Line voltage	Measurement below AC 100V
Communication interface	It has an RS232 interface, and stored data can be uploaded to a computer via software.
Communication line	One RS232 communication cable, 1.5m long.
Data preservation	The "HOLD" symbol indicates when data is held.
Data storage	2000 groups, the "MEM" storage indicator displays a "FULL" symbol to indicate that the storage is full.
Data access	The "READ" symbol indicates when viewing data.
Overflow display	The "OL" symbol indicates over-range overflow.
Current clamp low current indication	When using the selection method or the dual-clamp method for measurement, if the current signal received by CT2 (A clamp) is below 0.5mA, the display will show a " " symbol. In this case, the clamping direction of the CT2 (A clamp) current clamp should be checked.
Interference test	Automatically identifies interference signals; the "NOISE" symbol indicates an interference voltage higher than 5V.
Auxiliary grounding test	It has an auxiliary grounding resistance value testing function, ranging from 0.00kΩ to 30.00kΩ (100R+rC<50kΩ, 100R+rP<50kΩ).
Alarm function	When the measured value exceeds the alarm setting, a "beep-beep-beep" alarm will sound.
Battery voltage	When the battery voltage is low, a low battery symbol will be displayed, reminding you that the battery needs to be charged.
Automatic shutdown	Automatic shutdown after 15 minutes of power-on
Power consumption	Backlight: 25mA Max (Power consumption for backlight only) Standby: 25mA Max (backlight off after power-on) Measurement: 150mA Max (backlight off)
Quality	Main unit: 2.66kg (including battery) Total weight: 7.87kg (including test leads, grounding pin, and packaging)
Toolbox	It can support a weight of 200kg
Operating temperature and humidity	-10℃～40℃; below 80% RH
Storage temperature and humidity	-20℃～60℃; below 70% RH
Overload protection	Measure grounding resistance: AC 280V/3 seconds between each port of C(H)-E and P(S)-ES.
Insulation resistance	20MΩ or higher (500V between circuit and casing)
Pressure resistance	AC 3700V/rms (between circuit and casing)
Electromagnetic properties	IEC61326(EMC)
Suitable for safety regulations	IEC61010-1 (CAT III 300V, CAT IV 150V, pollution level 2); IEC61010-031; IEC61557-1 (Grounding Resistance); IEC61557-5 (Soil resistivity); JJG 366-2004 (Grounding resistance meter); JJG 1054-2009 (Clamp-on grounding resistance meter).

Product features and applications

Support dual‑clamp, 2‑wire, 3‑wire, 4‑wire and selective measurement methods
FFT+AFC dual anti‑interference technology, suitable for strong interference industrial environment
φ52mm large‑diameter clamp, compatible with thick grounding cables
Measure grounding resistance, soil resistivity, AC current, grounding voltage and leakage current
2000 groups data storage, backlight large screen, RS232 data upload and print
Lithium battery powered, automatic shutdown, data hold and over‑limit alarm

Prodection details

Power industry: substation, distribution room, transmission tower, power equipment grounding test
Communication industry: base station, computer room, communication tower equipotential bonding test
Construction & lightning protection: building lightning receptor, grounding grid acceptance inspection
Oil and petrochemical: oil field, storage tank anti‑static and explosion‑proof grounding measurement
Industrial equipment: factory electrical equipment, large machinery grounding safety detection
Daily maintenance: multi‑point parallel grounding, complex network rapid on‑site test