Clamp multimeter is a combination of current transformer and ammeter.The iron core of the current transformer can be opened when the wrench is tightened.The wire through which the current is measured can pass through the opening of the iron core without being cut off. The iron core closes when the wrench is released.
Usually use ordinary ammeter when measuring current, the circuitry needs to be cut down to measure ammeter access, this is very troublesome, sometimes the normal operation of the motor is not allowed to do so.At this point, it is much more convenient to use the Digital clamp meter , which can measure the current without cutting off the circuit.
Principle of Digital clamp multimeter
The measured circuit wire passing through the iron core becomes the primary coil of the current transformer, in which the current is induced by the current in the secondary coil.The meter that connects the secondary coil to the current meter indicates the current of the line being measured.The tongs can be changed by changing the dial of the switch.However, it is not allowed to operate with a charge when shifting gears.Pliers are generally not accurate, usually 2.5 to 5 levels.In order to be convenient to use, there are also transfer switches with different measuring ranges for measuring different levels of current and measuring voltage.
The characteristics of Electrical clamp meter
Small and light pliers.
40 a / 400 a AC/DC
400 v / 600 v AC, DC
Automatic shutdown function.
Data retention function.
Maximum display 4000 counts.
Auto reset function.
Design in accordance with international safety specifications iec 61010-1 cat.iii 300V
Use of Clamp voltage tester
Clip-on ammeter test current, be sure to clip into a measured conductor (wire). The clip into two (parallel) can't detect current. In addition, when using clip-on ammeter center (core) detection, detection error is small. The power consumption of electrical appliances product, use the line separator is more convenient, some line separator test current amplification can be 10 times, so the following 1 a current can be amplified again after detection. Using dc clip-on ammeter detecting dc current (DCA), if the flow of electric current, on the other hand, is showing negative. Can use this function to measure the battery is charging or discharge state.
True RMS detection
Average way clip-on ammeter through communication testing, testing the average of the sine wave, and will enlarge after 1.11 times (sine wave ac) value as the effective value displayed. Different sinusoidal waveform and waveform rate slanting wave are also displayed after 1.11 x magnification, so the indication error is produced. Thus, detection of sine wave waveform and slanting wave, please choose can directly test the true RMS clip-on ammeter.
The leakage detection
The leakage detection is different from the usual current detection. Two (single-phase 2-wire) or three (single-phase 3-wire and three-phase 3-wire) should be clamped.Also can grip the ground wire for testing. The insulation of the leakage current in the low voltage circuit testing management method, has become the primary means of judging. Since it is electrical equipment technical standards (1997 revision) confirmation, in the event of blackouts buildings and factories, not gradually to detect leakage current clamp table was used.
Precautions for use
When conducting current measurement, the position of the measured fluid should be placed in the center of the clamping port to avoid errors.
(2) should estimate the size of the current to be measured before measurement, choose the appropriate range, in the don't know the current size, should choose the maximum range, according to the pointer again reduced range, but not in the conversion range measurement.
To ensure accurate reading, the tester should keep the mouth clean and intact. If there is dirt, use gasoline to scrub it clean before measuring.
In measuring current below 5A, measurements should be made in circles in order to be accurate.
Flow cytometers cannot measure the current of bare wires to prevent electric shock and short circuit.
Keep the range split knob on top of the maximum range after completing your measurements.
Electrical measurement and measurement.