DC Current Probe
NOTES, REQUIREMENTS, INFORMATION, ETC.
For measuring larger DC currents (_ 1 A) by attaching clip around conductor in which current is flowing without breaking the circuit. No display of reading. Auxiliary unit for pocket digital multimeter without DC power clip. Also included with various engine testers. In this case a relative compression test per cylinder is also possible with the DC power clip by measuring the starter current.
Quality Assurance and Utility Value Retention:
- Adjust the zero point just before attaching the clip, or store the current zero value on the multimeter as a reference.
- Avoid extreme changes of temperature of the clip during measurement (e.g. avoid attachment near exhaust system). Because of its measuring principle, extreme changes in clip temperature will cause the zero point to drift.
- Ensure that the jaws are closed. Keep the surfaces of the jaws clean.
- If the clip is placed over several current-carrying cables, consider that the currents in each conductor are added together if the current flow direction is the same, or are subtracted if the directions are different.
- To improve measurement accuracy when measuring small currents, perform a direct current measurement with the multimeter (most multimeters have 10 A current measuring ranges).
- Observe the low supply voltage indicator and replace batteries as needed.
- The reading accuracy of clip-on probes can be tested by comparing measurements with an ammeter (multimeter or instrument shunt) connected in series in the lower measuring range. If the current-carrying cable is then passed through the jaws of the clip several times (e.g. coiled), the probe should indicate the product of conductor current x number of coils.
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