Application and Theory of the Clamp Ammeter
Clamp Ammeter, also known as clamp meter, is a special electrical instrument for measuring AC current. Generally used for measuring current in situations where the circuit is constantly open. Nowadays, multifunctional digital display or pointer display instruments are commonly used. However, the wide use of digital clamp Ammeter has added many functions of multimeter to clamp Ammeter, such as voltage, temperature, resistance, etc. Different functions can be selected through the knob, and the usage method is almost the same as that of a regular clamp watch. Universal digital multimeter.
Clamp Ammeter, as its name implies, its measuring mechanism is like a pair of pliers, which can be opened and closed. When measuring, open the mechanism, let the wire pass through the jaws, and then turn off the measuring current.
Clamp on Ammeter can measure AC and DC current on low-voltage lines without interrupting load operation.
1. The clamp meter made of electromagnetic current transformer can only measure AC current and cannot measure DC current
2. The clamp meter made of Hall current sensor can measure AC and DC currents.
The principle of clamp type Ammeter measurement is to use core penetrating current transformer to measure current. Clamp Ammeter can be pointer type, electronic type, single type or integrated with multimeter.
Measuring principle of clamp Ammeter
It uses a through core current transformer to measure current. Clamp Ammeter can be pointer type, electronic type, single type or integrated with multimeter. Photo: This UT-201 is the cheapest multimeter in Uniery. But it also costs tens of dollars. We'd better choose some brands of watches. The first brand watch has exquisite workmanship and more accurate measurement results. Secondly, branded watches are safer and should not be purchased at a low price.
Five main uses of clamp Ammeter
Purpose 1: Measure three-phase three-wire circuit current and three-phase four-wire zero line current
A clamp meter typically measures the current of a single wire. When measuring the three-phase three-wire load current, if two wires are clamped simultaneously, the indicated current value should be the current of the third wire.
The measurement method for three-phase four wire neutral line current is the same as measuring three-phase three wire circuit current, with the three-phase lines clamped simultaneously. The current value displayed at this time is the current value of the neutral wire.
Purpose 2: Clamp meter for measuring small currents
The clamp meter measures small current, and even if the gear is adjusted to the minimum gear, the reading is still not very accurate. Therefore, it is possible to wrap the wire around the clamping arm and read the current value. Then divide the current reading by the number of turns to obtain the actual small current value.
Purpose 3: Determine the name of the current in the line to determine whether the equipment operates normally. It needs to be determined based on the current measured on site. Therefore, it is important to determine what current it is.
Purpose 4: Measure the no-load current of nameless motors and determine the rated power
Estimation formula: divide the no-load current by zero eight to get the power close to the level.
The steps are as follows: Measure the no-load current value I of the motor, according to the empirical formula: p=I/0.8
Purpose 5: Measure the no-load current of a 380V welding machine without a nameplate, and determine the apparent power S
Estimation formula: The capacity of the 38th welding machine is equal to the no-load current I multiplied by 5.
