According to the measurement principle, pressure gauges can be divided into two categories: one is to measure the pressure according to the physical effect produced by the pressure on the object, such as piezoresistive pressure sensor and piezoelectric pressure sensor; The definition of pressure directly measures the magnitude of pressure, such as liquid column pressure gauges and digital pressure gauges.
In the production process, according to the size of the measured pressure signal, whether remote transmission, alarm or automatic recording is required, display requirements, characteristics of the measured medium (such as viscosity, temperature, corrosion, cleanliness, etc.), measurement accuracy, Ambient environmental conditions (such as temperature, humidity, vibration, etc.), whether explosion-proof is required to choose a suitable pressure gauge; that is, a pressure gauge customized according to the pressure range, a remote pressure gauge, and a digital display pressure control integrating pressure display control and alarm Devices, recording pressure gauges that need to collect and record data, special media need anti-corrosion pressure gauges, explosion-proof pressure gauges. In short, the correct choice of instrument type is an important prerequisite to ensure safe production and normal operation of the instrument.
1. Signal transmission distance: Digital pressure gauges, liquid column pressure gauges, buoy pressure gauges, etc. can be used to display the pressure on the spot. When remote pressure signals are needed or pressure signals are controlled, remote pressure gauges can be selected. Controlled pressure gauge, alarm pressure gauge, etc.
2. Number of measuring points: When multiple pressures need to be measured at the same time, a pressure inspection instrument can be selected.
3. Range: Select the appropriate pressure gauge range according to the measured pressure. Stable pressure, the measured pressure should fall between 1/3 to 2/3 of the range; pulsating pressure, the maximum pressure should not exceed 1/2 of the full range; high pressure, the maximum pressure should not exceed 3/5 of the full range.
4. Accuracy: Select according to the maximum measurement error allowed in the production process, taking into account economics, reliability and durability.
5. Dimensions: Digital display pressure gauges generally choose dial diameters of φ60mm, φ80mm, φ100mm; pointer instrument dial diameters are generally selected as φ150mm, which can be increased to φ200 ~ φ250mm under poor lighting conditions.
6. The characteristics of the measured medium, thick, easy to crystallize, corrosive or contain solid particles. The measured medium should use a flat film pressure gauge or a pressure gauge with a chemical seal; steam or high temperature medium should choose a stainless steel pressure gauge or install condensation Circle; special pressure gauges for special chemical media should be selected, such as pressure gauges for ammonia containing media, sulfur pressure resistant pressure gauges, etc.