Measurement times n=5, and the average value x=( 1+2+3+4+5)/5=3.

Variance d (x) = (1/n) ∑ (xi-x)? .

=( 1/5)[( 1-3)? +(2-3)? +(3-3)? +(4-3)? +(5-3)? ]。

=2。

ua = S =√D(x)=√2 = 1.4 142。

Calculation of sensitivity coefficient in uncertainty evaluation of engineering test Ou Zhang (Sichuan Electric Power Experimental Research Institute, Chengdu, Sichuan 6 10072)

In the evaluation of engineering test uncertainty, because the functional relationship of engineering test is often nonlinear, it is more complicated to get the sensitivity coefficient when synthesizing the uncertainty components.

There are some shortcuts to calculate the sensitivity coefficient. By mastering these methods, the sensitivity coefficient can be calculated more simply.

Extended data:

For example, to measure the internal energy u, enthalpy and entropy |s of a thermodynamic process, it is necessary to measure the pressure p, temperature r and specific heat v of the thermodynamic system. For example, to measure the resistivity p of a conductor in electrotechnics, it is necessary to measure the geometric parameters of the conductor: diameter d, length 2, and resistance ruler. By calculating P=, d2R/(4 1) can be obtained.

The measurement method of converting a measured object into several directly measurable quantities to measure, and then calculating or drawing according to the relationship (measurement formula) derived from the definition or law, so as to indirectly obtain the measurement results is called indirect measurement.

Baidu encyclopedia-indirect measurement