Meatest 9010+, User Manual

Page: 69 / 79

Voltage range summary: 0.200000 V – 1050.0000 V
Current range summary: 0.200000 mA – 30.00000 A
Electric power range: 0.04000 mW – 30.0000 kW
Frequency range: DC, 15.000 Hz – 1000.00 Hz
Energy period range: 2.000 s – 3600.000 s
Phase shift range:
0.00° – 359.99°
Phase shift uncertainty:
0.15° at 200 Hz and below
0.25° above 200 Hz
0.5° in 1050V range, 20 – 500 Hz
Uncertainty of DC power is determined by formula , where:
- dP is uncertainty of output power in %
- dU is uncertainty of set voltage in %, as per DCV specifications in chapter 8.1
- dI is uncertainty of set current in %, as per DCI specifications in chapter 8.2
This example calculates uncertainty of 4 W (20 V, 200 mA). Individual items in formula are calculated
like this:
-
dU = 0.0035 % + 40 µV = 0.0037 % of 20 V value
-
dI = 0.015 % + 6 µA = 0.018 % of 200 mA value
DC power uncertainty is then calculated as dP =

(0.0037
2
+ 0.018
2
+ 0.01
2
) = 0.021 %, which is also
the best DC accuracy achievable.
Uncertainty of AC power is determined by formula , where:
- dP is uncertainty of output power in %
- dU is uncertainty of set voltage in %, as per ACV specifications in chapter 8.1
- dI is uncertainty of set current in %, as per ACI specifications in chapter 8.2
- dPF is uncertainty of power factor in %
dPF is based on type of power units used, calculated by following formulas:
- for active power
- for reactive power
- for apparent power
where:
-

is set phase shift between voltage and current
- d

is uncertainty of set phase shift
dP =

(dU
2
+ dI
2
+ 0.01
2
)
dP =

(dU
2
+ dI
2
+ dPF
2
+ 0.03
2
)
dPF = [1 – cos (φ + dφ) / cos (φ)] ∙ 100
dPF = [1 – sin (φ + dφ) / sin (φ)] ∙ 100
dPF = 0