Mine Stray Current Measuring Instrument

FZY-3 Mining Stray Current Tester

I. Product Application
      The FZY-3 Mining Stray Current Tester is a highly sensitive, multi-range portable rectifier instrument with protective circuitry. Its features include a wide measurement range with ten ranges in total, capable of measuring both AC and DC stray voltage and stray current. It does not require a power source, making it safe and reliable.
This tester is suitable for measuring the current and voltage generated by rails, water pipes, cables, etc., in coal mine underground environments. It helps prevent premature detonation of electric detonators and other combustion accidents caused by stray current discharge, minimizing ignition sources within the mine to the greatest extent. 
II. Product Performance
      1. Measurement Range and Accuracy (as shown in the table below)

      2. Dimensions: 300mm × 220mm × 150mm
      3. Net Weight: 2.1kg
III. Usage and Precautions
      1. Before measurement, securely screw the test leads into the two terminals and adjust the pointer to the zero mark;
      2. Place the test leads connected to the terminals at the two points to be measured (e.g., rails, water pipes, cable sheaths, coal, ground, etc.). The two measurement points should be on different conductors, approximately 2 meters apart. Normally, measurements should be taken every 50–100 meters, or test points can be determined temporarily as needed. Set the selector switch to the appropriate range, and the meter reading, after conversion, will give the corresponding current value;
      3. During measurement, ensure the hard alloy tips of the probes make good contact with the measured object. The instrument should be placed horizontally to ensure accurate readings;
      4. If AC stray current is not detected at one point, also test for DC stray current, and vice versa;
      5. When measuring stray voltage values, the corresponding ranges are:
            50mA  corresponds to   0.2V              250mA     corresponds to    1.0V
            1.0A    corresponds to   4.0V               5.0A        corresponds to    20.0V
            10.0A  corresponds to   40.0V
            (i.e., the current value multiplied by 4 equals the voltage value)
      6. When the magnitude of the stray current is unknown, start with the largest range and gradually decrease to the appropriate measurement range;
      7. When the measured current exceeds 5A, the instrument should only be used for short-term measurement. For currents exceeding 10A, only instantaneous measurements are advisable to avoid damaging components and the instrument due to high current;
      8. When measuring DC stray current, if the pointer deflects in reverse, swap the test leads;
      9. When not in use, set the instrument to the "Off" position.

Note: The product is continuously updated and improved during production. The product appearance images are for reference only (subject to the actual product). Changes may be made without prior notice.