Many large-scale energy consuming equipment need to use vacuum pumps and vacuum units, such as vacuum drying, vacuum distillation, vacuum decompression and other processes. In order to provide efficiency and save energy, it is necessary to measure and control the vacuum degree of the equipment accurately and automatically. At present, most of the electric contact vacuum meters, resistance vacuum meters, thermocouple meters, etc. are still old-fashioned, with poor accuracy, instability and short service life. Of course, there are also imported equipment, but the imported products of vacuum measurement and control instruments and vacuum meters are very expensive, so how should we choose the vacuum meters with high cost performance when our ordinary equipment needs vacuum control?
The following points are for your reference. I hope they can help
First, considering the advanced nature of vacuum measurement mechanism, we should choose new type vacuum sensors, such as silicon integrated vacuum sensors, ceramic substrate thick film vacuum sensors, ceramic capacitor vacuum gauge, and so on. The traditional heat conduction type (thermocouple meter, resistance gauge, and pin) and so on, although the price is slightly lower, its accuracy is low and stable. Sex is poor, life is short, although there are also digital, but after all, it is a congenital deficiency.
Second, the measurement and control range of vacuum degree shall be selected from the working vacuum degree of vacuum equipment, rather than the limit vacuum degree of vacuum pump or unit. For example, the system adopts 2x rotary vane pump, and the limit vacuum degree can reach 0.5pa. However, due to the reason of air extraction efficiency, it is often used above 100Pa, so the lower limit of 0.1kpa measurement shall be selected (the lower the lower the limit, the more accurate it is The higher the demand, the higher the price.
Third, the measurement accuracy level and resolution should be selected reasonably. Generally, level 1.0 and level 0.5 should be selected for equipment. However, if it is used as precision vacuum measurement and control, measurement standard, etc., level 0.1 and high resolution instruments should be selected. For the selection of vacuum gauges used to measure the sealing of pipes, containers, radiators, air-conditioning refrigerator components, etc., ceramic diaphragm gauges can choose high-resolution instruments with accuracy of 0.5 and 0.25, but resolution of 1 pa, with high cost performance.
Of course, there are also important characteristics of chemical industry and other industries: explosion-proof and anti-corrosion requirements. Additional functions will increase the price. If the requirements are not high, it is not necessary to use special explosion-proof and anti-corrosion types. If the requirements are strict, of course, they cannot be sloppy.