Selection of pressure gauge range
Thread Content
Regarding the selection of the range for a pressure gauge, the question bank for instrument technicians suggests using elastic pressure gauges, with the maximum pressure not exceeding 3/4 of the gauge’s range. When the pressure being measured fluctuates significantly, the maximum pressure should not exceed 2/3 of the full range. To ensure accuracy, the minimum value of the pressure being measured should not be lower than 1/3 of the full range. Some sources state that the maximum pressure should not exceed 2/3 of the range, and in cases of large fluctuations in the measured pressure, it should not exceed 1/2 of the full range; again, to ensure accuracy, the minimum value should be at least 1/3 of the full range. Which of these two statements should be followed? Are there any standards regarding this?
Specifications for the Selection and Design of Automated Instruments (HG/T 20507-2014) 5.2.8 The selection of the measurement range for pressure measuring instruments shall meet the following requirements: 1. When measuring a stable pressure, the normal operating pressure value should fall within the range of 1/3 to 2/3 of the instrument’s range. 2. When measuring the pressure of a pulsating medium (such as the pressure at the outlet of pumps, compressors, and fans), the normal operating pressure should be within the range of 1/3 to 1/2 of the instrument’s measurement range.
\"Code for Selection and Design of Automation Instruments in Petrochemical Industries\" SH/T 3005-2016: 6.1.3 When measuring stable pressure, the normal operating pressure should be between 1/3 and 2/3 of the range. 6.1.4 When measuring pulsating pressure, the normal operating pressure should be between 1/3 and 1/2 of the range.
Specifications for the Selection and Design of Automated Instruments (HG/T 20507-2014) 5.2.8 The selection of the measurement range for pressure measuring instruments shall meet the following requirements: 1. When measuring a stable pressure, the normal operating pressure value should fall within the range of 1/3 to 2/3 of the instrument’s range. 2. When measuring the pressure of a pulsating medium (such as the pressure at the outlet of pumps, compressors, and fans), the normal operating pressure should fall within the range of 1/3 to 1/2 of the instrument’s measurement range
Is there something wrong with what’s stated in that instrumentation technician test booklet? Is the normal operating pressure 1/3 to 2/3, with a maximum of no more than 3/4? Is there such a specification?
Regarding the maximum pressure of the pressure gauge, there are no regulations specified in the standard codes; each organization can set it according to its own circumstances.