**9. Experimental validation**

170 Modern Metrology Concerns

case of voltage (current), we consider the effects of the small component, leakage, noise, and

*Vk*/*V*1) = (*Vk*/*V*1) *u*(

Considering the non-linearity of amplitude under the harmonic conditions in Section 5.2, the ratio of (*Vk*/*V*1) can be converted to [0.8(*Vk*/*V*1) + 0.2]. With the addition of the resolution

*Vk*/*V*1) =[0.8(*Vk*/*V*1)+0.2]2 *u*2(

I*k*/*I*1) = [0.7(*Ik*/*I*1) + 0.3]2 *u*2(

The uncertainty of harmonic active power can be calculated according to Eq. (8.1.5), where parameters *Vk*/*V*1, *Ik*/*I*1 are taken from the characterizing signal in Table 4.2.1, and

*Vk*), and *u*(

results in Tables 5.4.1, 6.3.1, 7.2.5, and 7.3.1, respectively. For the cases *k* = 0, 30, 60, and

Order 1 10 20 30 40 50 60 42 28 4.4 3.0 1.6 0.63 0.70 39 26 4.2 2.9 1.5 0.61 0.65 32 22 3.8 2.6 1.3 0.55 0.52 28 19 3.6 2.4 1.3 0.52 0.44 Table 8.3.1. Fiducial uncertainty of active power at 500 V, 20 A under the characterizing

In Table 8.3.1 the maximum estimated uncertainty (*k* = 2) is 42 W/VA, which is the uncertainty index of the harmonic active power. At 100 V and 5 A, however, the maximum

In practical measurement, in order to obtain the best uncertianty of measurement, for example in the important comparison, the parameters of *Vk*/*V*1, *Ik*/*I*1 may use of the measuring values instead of the values of the characteristic signal. When the measuring signal consists of only a few harmonics, the resolution component in eqn.(5.4.1), (6.3.1), (8.2.7), (8.2.8) may take smaller values according the practical case. In the NIM's standard

*Vk*).

*Vk*)+ 6.852.

*Ik*)+ 7.28 2.

*Vk*/*V*1). (8.2.7)

*Ik/I*1), (8.2.8)

*Ik*) are taken from the experimental

*u*(

component, a new expression is derived:

Eq. (8.2.6), *u*4, can be similarly treated.

Thus, Eq. (8.2.5) becomes

**8.3 Uncertainty evaluation** 

uncertainties *u*(

signal condition, *U* (

*u*2(

 *u*3 = [sin *<sup>k</sup>* (*Ik*/*I*1)] *u*(

 *u*4 = [sin *<sup>k</sup>* (*Vk*/*V*1) ] *u*(

*u*2(

The digital estimation of *u*3 and *u*4 can be provided.

*Vk*/*V*1), *u* (

estimated uncertainty (*k* = 2) is 36 W/VA.

90, the calculated results are shown in Table 8.3.1.

*Ik*/*I*1), *u*(

*Pk*/(*V*1*I*1))/(W/VA) (*k* = 2)

non-linearity.

The specifications of the standard equipment analyzed and determined in the abovementioned sections are validated in a series of experiments.
