ZST-121 Solid Insulating Material Volume Resistance and Surface Resistance Tester

ZST-121 Solid Insulating Material Volume Resistance and Surface Resistance Tester fully complies with the national standard GB1410-2006 Test Methods for Insulation Resistance, Volume Resistivity and Surface Resistivity of Solid Electrical Insulating Materials, and ASTM D257 Test Methods for DC Resistance or Conductance of Insulating Materials. This instrument, equipped with different measuring electrodes (fixtures), can measure the volume resistivity and surface resistivity or conductivity of different materials (solid, powder, or liquid). It is suitable for measuring the volume and surface resistance of various insulating materials in rubber, plastic, film, powder, liquid, solid, and paste forms. In addition to measuring resistance, this instrument can also directly measure weak currents.Test resistance.



II. Technical Specifications



































































No.  

Item

Parameter

1

Resistance measurement range

1×104Ω ～1×1018Ω

2

Current measurement range

2×10-4A～1×10-16A

3

Display mode

Digital LCD display

4

Built-in test voltage

10V , 50V, 100V, 250V, 500V, 1000V

5

Basic accuracy

1%

6

Operating environment

Temperature: 0℃～40℃, relative humidity <80%

7

Power supply

AC 220V, 50HZ, power consumption approx. 5W

8

Instrument dimensions

285mm× 245mm× 120 mm

9

Weight

Approx. 5KG

10

Small size, light weight, high accuracy

Dual display of resistance and current, stable performance, convenient reading

11

Makes measuring ultra-high resistance as simple as measuring ordinary resistance with a multimeter

Eliminates the inconvenience of multiplying coefficients at different test voltages or ranges as required by old-style high resistance meters




III. Working Principle



    According to Ohm's law, the measured resistance Rx equals the applied voltage V divided by the passing current I. The traditional high resistance meter works by fixing the measuring voltage V and obtaining the resistance value by measuring the current I flowing through a sampling resistor. From Ohm's law, it can be seen that since current I is inversely proportional to resistance, not directly proportional, the displayed resistance value is nonlinear. That is, when resistance is infinite, current is zero, so the zero position of the meter is at ∞, and the scale near it is very dense with low resolution. The entire scale is nonlinear. Moreover, when measuring different resistances, the voltage V also changes somewhat, so ordinary high resistance meters have poor accuracy and low resolution.

    This resistivity tester simultaneously measures the voltage V across the resistance and the current I flowing through it, uses a large-scale integrated circuit to perform the calculation of voltage divided by current, and then converts the result through A/D conversion to digitally display the resistance value. Even if the voltage V across the resistance and the current I flowing through it change simultaneously, the displayed resistance value does not vary like ordinary high resistance meters due to changes in the measured voltage V or current I. Therefore, even if the measuring voltage, measured resistance, power supply voltage, etc. change, the impact on the result is minimal. Its measurement accuracy is very high (patented), theoretically the error can be zero, and in practice the error can be as low as a few thousandths or ten-thousandths.



IV. Typical Applications



1. Measuring insulation material resistance (resistivity)

2. Measuring resistance and resistivity of antistatic materials

3. Measuring system resistance of raised floors in computer rooms

4. Measuring resistance of antistatic shoes and conductive shoes

5. Photodiode dark current measurement

6. Physics, optics, and materials research