MEWOI3900 Contact Type Ground resistance,Earth Resistance Online Tester/Meter

OEM/ODM Testing Instruments Manufacturer

  • Main Features:: Range:Ground Resistance:0.01Ω-2000Ω;Ground voltage:AC 0~600V 1:Ground Resistance on-line monitoring 2:Ground Voltage on-line monitoring 3:Measure equipotential bonding resistance 4:Measure Low value resistor
  • Model No.:: MEWOI3900
  • Name:: MEWOI3900 Earth Resistance Online Tester

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MEWOI3900 Contact Grounding Resistance Online Tester is used to monitor grounding resistance, equipotential connection resistance and grounding voltage of grounding system. The range of resistance is 0.01_~2000_, and the range of voltage is AC 0~600V. The grounding resistance is measured by precise three-wire method or simple two-wire method. The grounding voltage is measured by average rectification method. On-line detection and real-time monitoring are carried out. Users can choose RS232 or RS485 to communicate. According to the MODBUS communication protocol, users can redevelop, build a network, and realize remote multi-point online monitoring. 

MEWOI3900 grounding resistance online tester is composed of tester, monitoring software and so on. The tester is very intuitive with super large LCD display. It can set alarm critical value through its keys, and has sound and light alarm indication. The shell material has the characteristics of high and low temperature resistance, anti-corrosion, flame retardant and so on, which ensures the accuracy, stability and reliability of long-time on-line monitoring in the field, underground mine and indoor. The software can display the measured grounding resistance and grounding voltage in real time. It can automatically monitor and record the interval time through the detector or software. The interval time range is 1-999 hours. The data stored by the software can be automatically recorded to generate reports, which are convenient to save, save historical data, print and analyze.


1,Range:Ground Resistance:0.01Ω-2000Ω;Ground voltage:AC 0~600V
2,Ground Resistance on-line monitoring
3,Measure equipotential bonding resistance
4,Measure Low value resistor


On-line monitoring ground resistance, ground voltage, equipotential connection resistance, low resistance.
Power Supply
Standard: 12V±1VDC, 150mA Max.
Optional: 24V±1VDC.

(auxiliary ground resistance 100Ω±5%, voltage to ground<10V)
0~600V AC±1%rdg±3dgt1V
Measure Mode
Precise 3-wire measurement, simple 2-wire measurement.
Measure Method
Ground resistance: rated current change-pole method, measured current 3mA Max, 820Hz;
Voltage to ground: average value rectification method.
Data Mode
Display Mode
4-digital super-large LCD.
Measuring Indicator
During measurement, LCD count down display.
LCD Size
Display field: 124mm×67mm.
L×W×H: 190mm×117mm×54mm.
Measure Rate
Voltage to ground: about 2 times/second; ground resistance: about 30 seconds/time.
Measure Times
Over 5000 times(Measuring 10Ω for one time and take a pause for 30s).
Line Voltage
Measuring voltage to ground: measuring below AC 600V.
Instrument Interface
Pluggable terminal blocks: 9 pin connector.
Communication Method
RS485 (or optional RS232).
Communication Line
USB to RS485 communication line( or optionalUSB to RS232 communication line).
Range Shift
Data Storage
400 sets, flash display FULL icon to indicate storage is full.
Interval Time
Range of automatic monitoring interval time: 1-999 h.
Data Access
Data read function: READ icon display.
Overflow Display
Exceeding measuring range overflow function: OL icon display.
Power Consumption
Backlit : 20mA Max.
Standby: 25mA Max.
Measurement: 70mA Max.
Audible and visible alarm.
Power supply Voltage
When power supply voltage decreases to about 7.8V,    will display, reminding to replace the power.
Detector: 450g.
Working Humiture
-10℃~40℃; below 80%rh.
Storage Humiture
- -20℃~60℃; below 70%rh.
Overload Protection
Measurement ground resistance: E-P, E-C between each interfaces AC 280V/3 sec.
Insulation Value
Over 10MΩ(between circuit and enclosure 500V).
Withstand Voltage
AC 3700V/rms. (Between circuit and enclosure).

IEC61010-4-3,Radio frequency electromagnetic field≤1V/m.

Applicable Safety Rules
IEC61010-1, IEC1010-2-31, IEC61557-1,5, IEC60529(IP54), Pollution degree 2, CAT III 300V.
AccessoriesMeter*1,Power and Communication Cable*1,Aluminum Mounting Parts, Manual

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