The four major industrial parameters are temperature, pressure, flow rate, and liquid level.
I. Temperature (T) Temperature is a physical quantity indicating the degree of hotness or coldness of the measured object. According to the measurement methods of temperature instruments, they can be divided into two categories: contact type and non-contact type. Contact temperature measurement instruments mainly include thermometers, thermal resistors, and thermocouples. Non-contact temperature measurement instruments mainly include optical pyrometers, photoelectric pyrometers, radiation pyrometers, and infrared thermometers.
II. Pressure (P) The pressure acting on any object consists of two parts: the atmospheric pressure and the pressure of the measured medium (usually the gauge pressure). The total sum of these two parts of pressure acting on the measured object is called the absolute pressure. And ordinary industrial pressure gauges measure the gauge pressure value, that is, P gauge = P absolute – atmospheric pressure. Pressure measurement instruments can be divided into three categories: By the method of balancing the gravitational force with the measured pressure, directly measure the magnitude of the force per unit area, such as liquid column pressure gauges and piston pressure gauges; By the method of balancing the elastic force with the measured pressure, measure the magnitude of the elastic force generated by the deformation of the elastic element under pressure, such as Bourdon tube pressure gauges, bellows pressure gauges, diaphragm pressure gauges, and capsule pressure gauges; Utilize the physical properties of certain substances related to pressure, such as changes in voltage, resistance, or capacitance when under pressure, for example, pressure sensors.
III. Flow Rate (Q) In industrial production and control, the detection and control of fluid flow rate parameters are one of the most common parameters. There are various instruments for measuring flow rate, mainly including ultrasonic flowmeters, electromagnetic flowmeters, throttling flowmeters, and positive displacement flowmeters.
IV. Liquid Level (H) The liquid level refers to the height of the liquid level in a sealed container or an open container. Commonly used instruments for measuring the liquid level include ultrasonic level meters, glass plate level meters, differential pressure level meters, float level meters, float drum level meters, float magnetic flap level meters, radar level meters, radioactive level meters, and radio frequency admittance level meters.
Post time: Apr-13-2025