Resistive
A resistive sensor is a device that converts physical quantities such as displacement, deformation, force, acceleration, humidity, and temperature into resistance values. There are mainly resistance strain sensor, piezoresistive, thermal resistance, thermal, gas sensor, humidity sensor and other resistive sensor devices.
Frequency conversion power
The variable frequency power sensor performs AC sampling on the input voltage and current signals, and then connects the sampled values with the digital input secondary instrument through transmission systems such as cables and optical fibers, and the digital input secondary instrument operates on the voltage and current sampling values. , parameters such as voltage RMS, current RMS, fundamental voltage, fundamental current, harmonic voltage, harmonic current, active power, fundamental power, and harmonic power can be obtained.
weigh
A load cell is a force-to-electricity conversion device that can convert gravity into an electrical signal, and is a key component of an electronic weighing instrument.
There are many kinds of sensors that can realize the conversion of force to electricity, and the common ones are resistance strain type, electromagnetic force type and capacitance type. The electromagnetic force type is mainly used for electronic balances, the capacitive type is used for some electronic crane scales, and most of the weighing products use resistance strain load cells. The resistance strain load cell has a relatively simple structure, high accuracy, wide application, and can be used in a relatively poor environment. Therefore, resistance strain load cells have been widely used in weighing instruments.
Resistance strain type
The resistance strain gauge in the sensor has the strain effect of metal, that is, it produces mechanical deformation under the action of external force, so that the resistance value changes accordingly. There are two main types of resistance strain gauges: metal and semiconductor. Metal strain gauges are divided into wire type, foil type and film type. Semiconductor strain gauges have the advantages of high sensitivity (usually tens of times that of wire type and foil type) and small lateral effects.
Piezoresistive sensor is a device made by diffusion resistance on the substrate of semiconductor material according to the piezoresistive effect of semiconductor material. Its substrate can be directly used as a measuring sensor element, and the diffusion resistance is connected in the form of a bridge in the substrate. When the substrate is deformed by external force, each resistance value will change, and the bridge will produce corresponding unbalanced output.
The substrate (or diaphragm) materials used as piezoresistive sensors are mainly silicon wafers and germanium wafers. Silicon piezoresistive sensors made of silicon wafers are more and more sensitive materials. People pay more and more attention, especially to measure pressure. Solid-state piezoresistive sensors for speed and speed are the most common.
Thermal resistance
Thermal resistance thermometry is based on the characteristic that the resistance value of metal conductors increases with temperature. Thermal resistors are mostly made of pure metal materials, and platinum and copper are the most widely used. In addition, nickel, manganese and rhodium have begun to be used to manufacture thermal resistors.
The thermal resistance sensor mainly uses the characteristic that the resistance value changes with the temperature to measure the temperature and the parameters related to the temperature. This kind of sensor is more suitable for occasions where the temperature detection accuracy is relatively high. The most widely used thermal resistance materials are platinum, copper, nickel, etc., which have the characteristics of large temperature coefficient of resistance, good linearity, stable performance, wide operating temperature range, and easy processing. It is used to measure the temperature in the range of -200℃～+500℃.
