Measuring rangeVoltageDC 0~3,999 mV
DC 0~399.9V
AC 0~599.9V
Wide Various
Current0~1,999 mA
Resistance0~1,999 Ω
0~1999 MΩ
Frequency0~9,999 Hz
10~50 KHz
LCD displayMax, Min, Average
Input Impedance100 MΩAccurate measure on any kinds of soil
PrinterInternal1, 5, 10(Time)
Optional FunctionEarth resistance Measurement mode0~200Ω (0.1Ω)
200~2,000Ω (1Ω)
Dimention195 x 40 x 85mm

SD-21 is a device to measure [corrosion potential] flowing to prevent corrosion of gas pipes buried underground. It has an internal input resistance of 100 ㏁ and is applied to the domestic situation where there are many granite topography, so it is the lowest in any terrain. The error allows you to measure the most accurate value.
(General competitor products have an internal resistance of 1 ㏁ or 10 ㏁, and with these low internal resistance devices, the error is large where the land resistance is high).