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ST3123 Double Clamp Grounding Resistance Tester

  • ST3123
ST3123 Double Clamp Earth Resistance & Resistivity Tester
Double Clamp Earth Resistance Measurements with2, 3 Wires, Auto Range
Earth Resistivity (ρ) Measurement using WENNER method
* High test current up to 20A.
* Advanced Filtering method (based on FFT Fast Fourier Transform) reduces noise interference for obtaining stable measurements.
* Automatic and Manual selection of the Test Current Frequency in four bands (94/105/111/128Hz). In Automatic mod.
* Warning for excessive noise and high Auxiliary Earth Spikes resistance.
* Large Graphic Display with backlight for readings in poorly illuminated areas.
* Up to 999 measurement results can be saved in the memory and recalled on the display.
* The stored results can be transferred to a PC using software and a USB adaptor which are not included.
Earth Resistance Measurement
1: Earth resistance measurement with 2, 3wires and six ranges covering measurements from 0.03Ω to 19.99kΩ.
2: Also ideal for large earthing systems by the considerable test current of 20mA (max) yield-ing a high resolution of 0.001Ω on 2Ω range. 
3: Advanced Filtering method (based on “FFT” Fast Fourier Transform) reduces noise interference for obtaining stable measurements.
4: Warnings for excessive noise and high Auxiliary Earth Spikes resistance.
Earth Resistance Measurements with 2 and 3 Wires

Earth Resistivity Measurement
* The earth resistivity measurement is useful for soil surveys to establish the optimum earth electrode system design and site, to avoid extra cost of re-working electrode installations. It can be also suitable for geological investigations.
* Earth resistivity measurement is automatically calculated after having set the distance between Auxiliary Earth Spikes.
Measurement Method for Earth Resistivity (ρ)
Stick the four Auxiliary Earth Spikes into the ground deeply. They should be aligned at an interval of 1-100m. The depth should be 5% or less of the interval between the spikes.

The stored results can be transferred to a PC via USB adaptor.
* Up to 999 measurement results can be saved in memory.
* Data can be converted to CSV files.
2-Pole/3-PoleEarth Resistance Measurement
Resolution Measuring range Accuracy
0.01 W 0.0119.99 W ±(2% + 3dgt)
0.1 W 20.0~199.9 W
1 W 200.0~999.0 W
0.01KW 1.000~1.99 KW
0.01KW 2.0019.99 KW
Measure Resistance Coefficient “r
Tolerance Measuring range Accuracy
0.01 W 0.06 Ω  99.99 Ω.m ±(2% + 3dgt)
0.1 W 100.0 Ω  999.9 Ω.m
0.001kW 1.000 kΩ 9.999 KΩ.m
0.01kW 10.00 kΩ  99.99 KΩ.m
0.1 KW 100.0 kΩ  999.9 KΩ.m
1 KW 1000 kΩ  1999 KΩ.m
Value Range of Rh & Rs
Value Range of Rh & Rs Precision
Re<1.00Ω 2kΩ ±5%rdg.±1%fs5
1.00Ω≤Re<2.00Ω 3.5kΩ
2.00Ω≤Re =Rex100+5kΩRh,Rs<100kΩ
Measure Interference Voltage
Items Measuring Range Tolerance Precision
Interference Voltage (Ust) 50.0 V 0.1v ±(2% + 2)
Frequency of Interference Voltage (Fst) 16Hz ~500 Hz 0.1Hz ±(1% + 0.5Hz)

TRMS Clamp current
Measuring range Resolution(mA) Accuracy
0.0 mA ~ 99.9 mA 0.1mA ±(5 % of reading +5 digits)
100 mA ~ 999 mA 1 mA ±(5 % of reading +5 digits)
1.00 A ~ 9.99 A 0.01 A ±(5 % of reading + 2 digits)
10.0A ~ 19.9A 0.1A ±(5 % of reading + 2 digits)
Input resistance: 5 Ω/1W
Safety Standards
This instrument is in compliance with EN61010, EN61557-1 & EN61557-5
Insulation Level : II, double-insulated
Pollution Level: 2
Maximum Altitude  2,000m
Overvoltage Level: CAT III 250V (firewire VS earth wire)
Basic Features
Dimensions: 270 (length) x 190 (width) x 80 (height) mm
Weight (including batteries): Approx. 1,700g
Power Supply
Batteries: 8 pcs batteries (1.5 V – R14G – SIZE C)
Low battery:The battery power is running out when appears.
Battery life:Meauring for 1,000 times
Fuse: F100 mA
Auto power-off: This instrument will shut down 5 minutes after the last instruction sent from PC or function selection.
Features: 102mm * 86mm standard LCD display
Storage capacity: 999 measured values at maximum
Connecting port: USB data cable for connecting to PC (data segregation has been preset)
Standard Accessories
1 pcs Current clamp
Black: 6mm; Red: 15mm; Blue: 30mm; Green: 6mm
User manual
Canvas bag
Optional Accessories
PC software and USB data cable

Product Enquiry
Address: Room 606, 2nd building, Animation Park, No.5 Yuehai Rd, Nanshan District, Shenzhen GuangDong China. 
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