Usage Methods and Precautions
1. Before measurement, screw the test rod wires into 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., 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 determine test points temporarily as needed. Set the selector switch to the appropriate gear, and the meter reading, after conversion, will give the corresponding current value.
3. During measurement, ensure the hard alloy tip of the measuring probe makes good contact with the object being measured, and the instrument should be placed horizontally to ensure accurate readings.
4. When no AC stray current is detected at a location, also test for DC stray current, and vice versa.
5. When measuring stray voltage values, the gear settings are: 50mA corresponds to 0.2V, 250mA to 1V, 1A to 4V, 5A to 20V, and 10A to 40V. (i.e., 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 the appropriate measuring gear is found.
7. When the measured current exceeds 5A, the instrument should only be used for short-term measurements; when it exceeds 10A, only for instantaneous measurements, to avoid burning out components and the meter due to high current.
8. When measuring DC stray current, if the meter pointer deflects in the reverse direction, simply swap the test leads.
9. When the instrument is not in use, set it to the "Off" position.
Performance
Measurement Range and Accuracy Class of the Instrument
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Measurement Range
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Measurement Accuracy
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Remarks
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Current Gear
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0-50mA-250mA
-1A-5A-10A
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AC ±5%
DC
±2.5%
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Before use, the pointer must be adjusted to zero position, i.e., zero adjustment.
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Voltage Gear
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0-0.2V-1V
-4V-20V-40V
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