The FZY-3 Mine Stray Current Tester is a portable rectifier instrument with high sensitivity and multi-range protection circuit.
Its characteristics are: wide measurement range, with a total of twenty ranges, capable of measuring AC/DC stray voltage and stray current separately, requiring no external power supply, safe and reliable.
It is suitable for testing the current and voltage generated by steel rails, water pipes, cables, etc. in underground coal mines, preventing premature detonation of electric detonators and other explosion accidents caused by stray current discharge, minimizing fire sources in the mine.
Detailed Introduction of Mine Stray Current Tester
I. Purpose
The FZY-3 Mine Stray Current Tester is a portable rectifier instrument with high sensitivity and multi-range protection circuit.
Its characteristics are: wide measurement range, with a total of twenty ranges, capable of measuring AC/DC stray voltage and stray current separately, requiring no external power supply, safe and reliable.
It is suitable for testing the current and voltage generated by steel rails, water pipes, cables, etc. in underground coal mines, preventing premature detonation of electric detonators and other explosion accidents caused by stray current discharge, minimizing fire sources in the mine.
II. Performance
Measurement range and accuracy class of the instrument
| Measurement Range | Measurement Accuracy | Remarks | |
| Current Range |
0-50mA-250mA -1A-5A-10A |
AC ±5% DC ±2.5% |
Before use, the pointer must be adjusted to zero position, i.e., zero adjustment |
| Voltage Range |
0-0.2V-1V -4V-20V-40V |
III. Usage Methods and Precautions
1. Before measurement, screw the test rod wires onto the two binding posts respectively, and adjust the meter pointer to the zero scale line.
2. Place the test rods connected to the binding posts on the two points to be measured (e.g., steel rails, water pipes, cable sheaths, coal, earth, etc.). The two test points should be on different conductors, with a distance of about 2 meters. Normally, measure once every 50-100 meters, or temporarily determine test points as needed.
Set the selector switch to the appropriate range, and the meter reading, after conversion, gives the corresponding current value.
3. During measurement, ensure good contact between the hard alloy tip of the measuring probe and the object under test. The instrument should be placed horizontally to ensure accurate readings.
4. When AC stray current cannot be measured at a location, DC stray current should also be tested, and vice versa.
5. When measuring stray voltage values, the corresponding ranges are: 50mA corresponds to 0.2V, 250mA to 1V, 1A to 4V, 5A to 20V, and 10A to 40V.
(That is, the current value multiplied by 4 gives the voltage value)
6. When the magnitude of stray current is unknown, first set to the maximum range, then gradually decrease until an appropriate measuring range is found.
7. When the measured current exceeds 5A, the instrument should only be used for short-time measurement. When the measured current exceeds 10A, the instrument should only be used for instantaneous measurement.
