Soviet vintage ammeter voltmeter M 231 Russian portable measuring device

Includes technical passport, technical description and instruction manual in Russian Ammeter-voltmeter portable multi-range magnetoelectric system M231 is designed to measure the strength and voltage of direct current, including corrosion measurements on rail tracks of electrified transport and underground metal structures. TECHNICAL DATAAccuracy class 1.5Amp voltmeter has a symmetrical scaleMeasurement range: Current: 0.005-0-0.005: 0.05-0-0.05: 0.1-0-0.1; 1-0-1;5-0-5; 10-0-10A; voltage: 75-0-75 mV: 0.5-0-0.5; 1-0-1; 5-0-5; 10-0-10; 50-0-50;100-0-100V The input impedance of the ammeter when working as a voltmeter is 20000 ohm/V. 2.5. Voltage drop when operating as an ammeter in the measurement range from 0.005-0-0.005 to 1-0-1 A, not more than 0.5 V: and in the measurement range from 5-0-5 to 10-0-10 A, not more than 1 V The main error at all scale marks does not exceed + -1.5%. The basic error is expressed as a percentage of the sum of the final values of the scale. The working position of the ampervoltmeter is horizontal Change in the ampervoltmeter readings caused by the temperature deviation from minus 30 to plus 40°C does not exceed +1.2% for every 10°C temperature change. +0.5% 2.10. The settling time of the moving part of the device is not more than 3 s Insulation test voltage 2 kv. The ampervoltmeter withstands without damage shaking with a maximum acceleration of 30 m/s at a frequency of shocks from 80 to 120 per minute for 2 hours. The mass of the ampervoltmeter is not more than 1.4 kg.