Photo - acoustic infrared detectors operate based on the pressure waves emitted by SF6 molecules when they are illuminated by monochromatic infrared light. Specialized microphones detect the acoustic signal, which is directly proportional to the energy absorbed. Sensitivities as low as 0.01 μl/l can be attained, far surpassing those of other methods. However, the response time of approximately 15 s restricts the use of this device for leak localization.Electron capture detectors utilize a ß - pa

Meters are generally designed to measure specific quantities. For example, the unit of current is the ampere, and the device used to measure current is called an ammeter. A rectifier ammeter employs a moving coil in conjunction with a rectifier to measure current. The primary function of the rectifier is to convert alternating current into direct current. This conversion is necessary because the moving - coil mechanism in the rectifier ammeter is typically designed to operate based on direct cur

Definition: A photoelectric tachometer is a device that measures the rotational speed of a machine's shaft or disc by utilizing light. Its essential components include an opaque disc with holes along its periphery, a light source, and a light - sensing element (it should be noted that the original text's mention of "laser" might be a misnomer; typically, a photodetector is used. A laser could be a part of some more complex set - ups, but not in a basic photoelectric tachometer configuration). Th

An electron capture detector (ECD) is a highly sensitive instrument capable of detecting sulfur hexafluoride (SF6) at concentrations below 1 ppmv. This sensitivity stems from SF6's high electron attachment coefficient, which refers to its strong ability to capture electrons. The free electrons available for attachment to SF6 molecules are generated by a radioactive source within the ECD. Typically, the ECD employs a radioactive emitter in the form of a metallic membrane coated with the radionucl

Over - voltage and Over - current Aspects Ferroresonant over - voltage: In a non - effectively earthed neutral system, the magnetic circuits of equipment such as transformers, voltage transformers, and arc suppression coils may saturate, potentially triggering ferroresonance. The resulting over - voltage can increase the excitation current of the voltage transformer by dozens of times. Operating under high voltage and large current for an extended period causes the temperature of the transformer

Definition of Electromagnetic Flow MeterAn electromagnetic flow meter is a device used to measure the flow of liquid as it passes through a pipeline. More specifically, electromagnetic flow meters are used to measure the flow rate of electrically conducting fluids. An electrically conductive liquid refers to any liquid that allows an electric current to pass through it.Working Principle of Electromagnetic Flow MeterElectromagnetic flow meters operate based on Faraday's Law of electromagnetic ind

Principles of the Half-Deflection MethodThe Half-Deflection Method is a technique used to measure the internal resistance of a galvanometer. This method is adopted primarily because it is relatively simple and does not require additional precision instruments or complex circuit setups. Below are the reasons for using the half-deflection method along with its underlying principles:Basic Principles of the Half-Deflection MethodInitial State: First, connect the galvanometer to a known voltage sourc

Applications of Current Transformers in Industrial SettingsCurrent Transformers (CTs) play a crucial role in industrial applications, primarily used for measuring and protecting power systems that handle large currents. Below are the main uses of current transformers:1. MeasurementHigh-Precision Monitoring: CTs can proportionally convert large primary currents to smaller secondary currents, allowing standard measurement instruments (such as ammeters and wattmeters) to safely and accurately measu

How Partial Discharge Testing Enhances the Reliability of High-Voltage Equipment and Its LimitationsPartial discharge testing (PD Test) is a crucial method for assessing the insulation performance of high-voltage equipment. By detecting and analyzing partial discharge phenomena, potential insulation defects can be identified, thereby enhancing the reliability of high-voltage equipment. Below are the specific mechanisms through which partial discharge testing improves reliability and its limitati

Methods to Determine Coil TemperatureThere are several methods to determine coil temperature, and the choice depends on the application scenario, required accuracy, and available equipment and technology. Below are some commonly used methods to determine coil temperature:1. Direct Measurement Methodsa. Thermocouples Principle: Thermocouples utilize the thermoelectric effect produced by the contact of two different metal materials to measure temperature. Usage: Install the thermocouple probe near