Analysis of set point deviation of electric contact pressure gauge
Analysis of set point deviation of electric contact pressure gauge
Electric contact pressure gauge is a key instrument, which is used to display the output of pressure, control signal or alarm signal, realize the functions of pressure monitoring, liquid level monitoring and control, ensure the normal operation of the system and ensure the accuracy. It is of great significance to the safety production of enterprises. The verification methods and verification items of electric contact pressure gauges have clear requirements in jjg52-2013 verification regulation of elastic element type general pressure gauges, pressure vacuum gauges and vacuum gauges [1] (hereinafter referred to as "verification regulation"). This paper mainly analyzes the meaning of the set point deviation of the electric contact pressure gauge and the concepts of "error" and "Deviation". Through the analysis, the data processing of the set point deviation of the electric contact pressure gauge is discussed.
1 setpoint deviation
1.1 different understanding of setpoint deviation
#Recently, a magazine published an article [2] on verification of set point deviation of electric contact pressure gauge, which proposed that the set point deviation in 3.1.2 of the verification regulation
Difference is defined as the difference between the set value and the measured actual value when the output variable is output according to the specified requirements (as defined in 7.10 of jjf1008-2008[3]), and the difference between the upper switching value and the set point pressure value in 7.3.7.1 set point deviation verification C in the regulation is the boost set point deviation, and the difference between the lower switching value and the set point pressure value is the depressurization set point deviation. Due to the unclear concepts before and after, it brings some troubles to the verification personnel in the data processing process. The definition of 7.10 set point deviation in jjf1008-2008 pressure measurement terms and definitions is understood as the difference between the set value and the actual value read on the standard, that is, "set point deviation = set value - actual value".
1.2 analysis of setpoint deviation
First, let's learn the two terms "error" and "Deviation". Both of them have non positive or negative symbols. The perceptual values of the same quantity are equal but the symbols are opposite. The error is used to express the accuracy of the measured value, indicating that the measurement result deviates from the true value, which is a difference. In jjf1001-2011 technical specification for general Metrological Terms and definitions [4], it is defined as "the measured value minus the reference value", where the reference value is the actual value, the agreed (true) value, the measured value of a higher level measurement standard device, etc., that is, "error = measured value - true value (reference value)". The deviation is used to express the accuracy of the measured value, indicating that the deviation of the measurement result from the given value can be divided into upper deviation and lower deviation. In jjf1001-1998 general measurement terms and definitions [5], it is defined as "a value minus its reference value" (deleted in jjf1001-2011). It should be noted here that "one value" refers to actual value, agreed (true) value, measured value of higher-level measurement standard device, etc; The reference value is a reference condition, which is the indicated value, given value, set value, etc., rather than the actual value and agreed (true) value, that is, "deviation = actual value (a value) - set value (reference value)". There is a difference between the reference value of error and the reference value of deviation, but the meaning is different. Therefore, before verification, Shou should first clarify which concept is "error" or "Deviation", and should not be confused.