The purpose of the ohm meterOhm meter is an electrical measurement tool specially used to measure resistance values, and its working principle is based on Ohm's law of closed circuits. The following are the main uses of ohmmeters: Direct resistance measurement: The ohmmeter can directly measure the resistance value of the resistor in the circuit, which is very useful for the design and fault diagnosis of electronic circuits. Judge the circuit status: By measuring the resistance, the ohmmeter can

How to Determine Whether an Ammeter or Voltmeter Is Connected in Series in a Circuit?Determining whether an ammeter or voltmeter is connected in series in a circuit can be done by observing the instrument's connection method and its readings. Here are specific ways to do this:How to Determine if an Ammeter Is Connected in Series?Physical Connection Direct Observation: The most straightforward method is to look at how the ammeter is connected to the circuit. An ammeter should be connected in seri

Accuracy and calibrationFlux leakageIn open-close current transformer, the opening and closing of the iron core will lead to leakage of magnetic flux. Because the core is not a complete, continuous loop like a solid core transformer, part of the magnetic field line may escape through the gap. This can lead to inaccurate ratios. For example, if the transformer is designed with a ratio of 100:1 (the ratio of primary current to secondary current), magnetic flux leakage may bias the actual ratio, re

A power system Fault Recorder, also known as a fault recorder or fault recorder, is a device used to record faults and related events occurring in a power system. This type of equipment plays a vital role in the monitoring, protection and maintenance of power systems. The following is a detailed description of the power system fault recorder:Feature Data acquisition: The fault logger can collect all kinds of data in the power system in real time, including voltage, current, frequency, phase Angl

Temperature sensors and pressure sensors are two different types of sensors that are each designed to detect different physical quantities - temperature sensors for temperature and pressure sensors for pressure. Nevertheless, in some specific cases, temperature sensors can be used indirectly to infer changes in pressure, but this is not a direct or accurate method. Here are some related discussions:The difference in principle Temperature sensor: Usually designed to detect the temperature of an o

Galvanometer is an instrument used to detect weak currents. In general, a negative current has a similar effect on a galvanometer as a positive current, but it may behave a little differently in the following ways:Pointer deflection directionDetermine current directionThe direction of the galvanometer pointer deflection is related to the direction of the current passing through it. Normally, when current flows from a particular direction of the galvanometer, the pointer deflects in one direction

To determine if the voltmeter is damaged by measuring high voltage or current, you can check it in several steps. Here are some ways to help you diagnose the status of your voltmeter:Observe the appearanceFirst check the appearance of the voltmeter for obvious signs of damage, such as cracks, burn marks, melted parts, or smoke marks. These may be visual evidence of damage to the voltmeter.Measure the reference voltageIf your voltmeter has a known reference voltage source (such as a standard batt

What is Capacitive Sensor?Capacitive sensor definitionCapacitive sensor is a kind of sensor based on capacitance change to detect the change of physical quantity.Working principleThe working principle of capacitive sensors is based on the definition formula of capacitance: C is capacitance. ϵ is the permittivity of the medium. A is the effective area between the plates. d is the distance between the two plates.Capacitive sensors detect changes in physical quantities by changing one or more of th

Winding Resistance Test DefinitionThe winding resistance test of a transformer checks the health of transformer windings and connections by measuring resistance.Procedure of Transformer Winding Resistance MeasurementFor star connected winding, the resistance shall be measured between the line and neutral terminal.For star connected autotransformers the resistance of the HV side is measured between HV terminal and IV terminal, then between IV terminal and the neutral.For delta connected windings,

Temperature Rise Test DefinitionA temperature rise test of a transformer checks if the temperature increase of its winding and oil meets specified limits.Temperature Rise Test for Top Oil of Transformer First, the LV winding of the transformer is short-circuited. Then one thermometer is placed in a pocket in the transformer top cover. Other two thermometers are placed at the inlet and outlet of the cooler bank respectively. The voltage of such value is applied to the HV winding that power input