3.3.4 Intrinsic Uncertainty and Operating Uncertainty
These megohmmeters comply with standard IEC 61557, which requires that the
operating uncertainty (called B) must be less than 30%.
In insulation and continuity measurements:
where:
A = intrinsic uncertainty
E
1
= influence of the reference position ± 90°
E
2
= influence of the supply voltage within the limits indicated by the
manufacturer
E
3
= influence of the temperature between 0 and 35°C (32 and 95°F)
3.4 Power Supply
The instrument is powered by six 1.5V alkaline AA (LR6) batteries.
The voltage range ensuring correct operation is from 6.6V to 9.6V.
Typical life between charges:
■ 1500 5-second insulation measurements at 1000V for R = 1 MΩ, at the
rate of one measurement per minute.
■ 3000 5-second continuity measurements, at the rate of one
measurement per minute.
3.5 Environmental Conditions
Indoor use
Range of operation: -20 to +55°C (-4 to 131°F) and 20 to 80% RH
Range of storage (without batteries): -30 to +80°C (-22 to 176°F) and 10 to 90%
RH without condensation
Altitude: <2000m (6562ft)
Degree of pollution: 2
