I. Overview

The insulation resistance meter (megohmmeter) is a nationally mandatory verification measuring instrument, with its verification regulation being JJG622-89. The main standard devices of the verification equipment are the high-voltage high-resistance box and the high-voltage voltmeter. The GZX92A insulation resistance meter verification equipment integrates the high-voltage high-resistance box (high-resistance output part) and the high-voltage digital voltmeter (voltage input part) into one unit.

The measurement upper limit of the resistance output part in the verification equipment is 200GΩ, with a nominal working voltage of 5kV. The device is designed with independent leakage terminals and grounding terminals, showing no significant instability, short circuit, or open circuit phenomena during measurement. It meets the requirements of the JJG622-97 insulation resistance meter verification regulation and the JJG166-93 DC resistor verification regulation. It can be used for the verification of various types of pointer-type insulation resistance meters.

The resistance output part of the verification equipment uses a patented rolling high-voltage switch, which can still meet the verification regulation requirements after 100,000 uses. It has a long technical and mechanical lifespan. The nominal measurement voltage of the voltage measurement part in the verification equipment is 5kV, with an input impedance ≥10GΩ. This device can measure the open-circuit voltage, median voltage, and peak voltage of the megohmmeter.

II. Main Technical Parameters

1. Resistance Output (High-Voltage High-Resistance Box) Part

1.1 Accuracy Class and Working Voltage (Current) of the Resistance Output Part

1.2 Adjustment Range: 100Ω～200GΩ, with a resolution of 100Ω

1.3 Operating Environmental Conditions

1.3.1 Reference Temperature Range: 20～25℃

1.3.2 Nominal Operating Temperature Range: 18～28℃

1.3.3 Reference Humidity Range: 40～60%

1.3.4 Nominal Operating Humidity Range: 25～75%

1.4 Resistance Variation Limit: The variation caused by a single influencing factor under reference conditions

★ a is the accuracy class of the resistance dial in the resistance output part of the verification equipment (each resistance dial has a different a value)

1.5 Insulation Resistance: The insulation resistance between the circuit of the resistance output part of the verification equipment and any other external metal without electrical connection, measured at the nominal voltage, is not less than 5TΩ.

1.6 Insulation Strength: Between the circuit of the resistance output part of the verification equipment and the test reference ground point, it should withstand an actual sinusoidal AC voltage of 11kV at a frequency of 45～65Hz for 1 minute without breakdown or flashover.

1.7 The residual resistance at the output terminals of the resistance output part of the verification equipment should be <0.1Ω, with a variation of <0.01Ω.

1.8 Dimensions: 442mm×270mm×145mm

1.9 Weight: <5kg

2. Voltage Measurement (High-Voltage DC Digital Voltmeter) Part

2.1 Measurement Range: 0～5500V

2.2 Accuracy: ±(1% reading ±1 digit)

2.3 Power Supply: DC9V

2.4 Input Resistance: ≥10GΩ

2.5 Display: Four and a half digits, LCD display

2.6 The peak voltage measurement circuit meets the requirements of Figure 3 in the JJG622-97 insulation resistance meter verification regulation.