Pressure gauge how to choose correct?

In industrial production, in addition to the thermometer, common measuring instrument is the pressure gauge, the following will tell us the pressure gauge how to choose the right? A, when selecting a stable pressure in the range, the maximum pressure gauge range choose close to or greater than the normal pressure measurement value of 1. 5 times; When measuring fluctuating pressure, the maximum pressure gauge range choose close to or greater than 2 times of measurement value of normal pressure; When measuring machine pump outlet pressure, the maximum pressure gauge range choose close to export pump and maximum pressure value; When measuring high pressure, the maximum pressure gauge range selection should be greater than the maximum pressure measured value of 1. Seven times. In order to ensure the pressure measurement precision, minimum pressure measurement value should be higher than 1/3 of the pressure gauge measuring range. Second, the type selection pressure & gt; 0. When 4 mpa, can choose bourdon tube pressure gauges; Pressure & lt; 0. 04 mpa, can choose bellows and bellows pressure gauge; Measuring sticky, easy to crystallization, corrosive, containing solid particles, diaphragm pressure gauges can be used or with chemical sealing device; Steam or above 60 ℃ medium pressure measurement should choose stainless steel pressure gauge or install the cooling loops; Pulse pressure measurement should be additional damper or seismic pressure gauge; When measuring dust contained gas should be set filter; Contain liquid gas pressure measurement should be set when the gas liquid separator; Should choose special pressure gauge to measure some chemical medium: the pressure measurement using ammonia containing ammonia medium with pressure gauge, the pressure measurement using oxygen containing oxygen pressure gauge, for measuring pressure acetylene using acetylene pressure gauge, the sulfur sulfur resistance pressure gauge for the pressure medium; High pressure gauge ( More than 10 mpa) Should have pressure relief safety facilities.