Key points for annual calibration of clamp watches
The current clamp meter measures current through non-contact means, making it safer and more convenient to obtain measurement values. The current clamp usually also has additional measurement functions, such as voltage and continuity. Clamp watches generally require annual calibration to ensure that they meet the manufacturer's technical specifications.
The following are 7 important factors to consider when calibrating a clamp table:
1. Clamp shaped watches come in various shapes and sizes.
The design of the jaw size makes the calibration process somewhat difficult and requires the selection of corresponding calibration equipment.
2. Most clamp watches today are multifunctional.
In addition to current, most clamp meters can generally measure voltage, resistance, continuity, and other common functions of digital multimeters,
Not all calibrators are competent for their job.
When the output is high, many calibrators limit the continuous output of large currents. In addition, you must use a calibrator with sufficient accuracy and a compliant voltage sufficient to drive the coil. Fluke uses "L-COMP" (induction compensation) technology to increase the compliance voltage to drive inductive loads.
The coil inductance can cause faults, so it is important to avoid current sources that are not designed for current coils. The transient when turning on and off the current may cause the current source to trip.
4. The winding (number of turns) and range of the current coil are very important.
The number of turns of the coil used must be sufficient to test the entire current range of the current clamp. The winding of the coil determines the amount of current. For example, when the calibrator is 50 turns and outputs a current of 20 A, a maximum current of 1000 A will appear on the clamp meter.
5. Do not ignore attachments.
Some clamp meters may be equipped with flexible current probes, such as Fluke iFlex, which must be calibrated together with the clamp meter.
6. High current will generate heat.
The design of the current coil must be able to dissipate as much heat as possible. The coil usually has a maximum operating time indicator at higher currents.
7. Positioning is very important.
When aligning the clamp meter with the current coil, attention should be paid to the current clamp stray field and position sensitivity. Avoid interference fields from other devices and current wires. Pay attention to the alignment marks on the clamp gauge. Align the axis of the clamp gauge parallel to the coil axis, and align the jaw plane perpendicular to the coil wire.
