● Operating uncertainty
Operating uncertainty (B) is an error obtained under the nominal operating
conditions, and calculated with the intrinsic error (A), which is an error of the
instrument used, and the error (En) due to variations. According to
IEC61557, the maximum operating error should be within ± 30%.
● Operating uncertainty in insulation resistance measurements (IEC61557-2)
* Formula:
A Intrinsic uncertainty
E
1
Not applicable
E
2
Variation due to changing the Battery voltage
(till the battery indicator becomes empty” ”)
E
3
Variation due to changing the temperature
(-10ºC to 50ºC)
* E1 is not applicable since this is a digital instrument.
* The measuring range to keep operating uncertainty of ± 30% is the same
as the 1st effective measuring range.
● Operating uncertainty in earth resistance measurements (IEC61557-5)
* Formula:
A Intrinsic uncertainty
E
1
Not applicable
E
2
Variation due to changing the Battery voltage
(till the battery indicator becomes empty” ”)
E
3
Variation due to changing the temperature
(-10ºC to 50ºC)
E
4
Variation due to series interference voltage
16·2/3 Hz, 50 Hz, 60 Hz, 10 V DC
400 Hz: 3 V
E
5
Variation due to resistance of the auxiliary earth
electrode
20Ω range: 0 – 2 kΩ
200Ω range: 0 – 20 kΩ
2000Ω range: 0 – 50 kΩ
* The measuring range to keep operating uncertainty of ± 30% is within
5.00 Ω – 2000 Ω.
w ww . .com
information@itm.com1.800.561.8187
To Next Page
Loading...
Need help?
General
