Instructions and precautions for using the FZY-3 Stray Current Tester:
1. Before measurement, screw the test rod wires tightly into the two binding posts, 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., rails, water pipes, cable sheaths, coal, ground, etc.). The two test points should be on different conductors, with a distance of about 2 meters. Normally, measure every 50-100 meters, or temporarily determine test points as needed. Set the 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 meter should be placed horizontally to ensure accurate readings.
4. If no AC stray current is measured at a location, also test for DC stray current, and vice versa.
5. When measuring stray voltage values, the 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 stray current magnitude is unknown, first set to the maximum range, then gradually decrease until the appropriate measuring range is found.
7. When the measured current exceeds 5A, the instrument should only be used for short-term measurements. When the measured current exceeds 10A, the instrument should only be used for instantaneous measurements to avoid burning out components and the meter.
