Megger BMM500 Series User Manual page 18

Specification
Basic and service errors for Insulation and
Resistance ranges
The basic error is the maximum inaccuracy of
the instrument under ideal conditions, whereas
the service error is the maximum inaccuracy
taking into effect of battery voltage, temperature,
interference, and system voltage and frequency,
where applicable. After determining the service
e r r o r, we can then calculate the measurement
range. This is the range of measurement over
which the error in service is less than 30% of the
reading. Digital instruments are affected by the
number of digits error – for example a value
0,10Ω measured with the continuity range may
give a display in the range 0,07Ω to 0,13Ω which
is a maximum error of 30%. Therefore the
measurement range measuring low resistance
is 0,10Ω to 99,9Ω. When checking that a
measurement does not exceed a limit, the s e r v i c e
error needs to be taken into account and these
tables enables this to be done quickly and easily.
These will guarantee that the value being
measured is greater than or less than the limit
value specified as appropriate.
Insulation Resistance – MΩ
Limit Min. Limit Min.
Indicated Indicated
Reading Reading
0,10 0,14 2,00 2,12
0,20 0,25 3,00 3,16
0,30 0,35 4,00 4,20
0,40 0,46 5,00 5,24
0,50 0,56
0,60 0,66
0,70 0,77
0,80 0,87
0,90 0,98
1,00 1,08
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