Megger BMM2500 Bedienungsanleitung Seite 24

Basic and service errors for
Insulation and Resistance ranges.
The basic error is the maximum inaccuracy of the instru-
ment under ideal conditions, whereas the service error is
the maximum inaccuracy taking into effect of battery volt-
age, temperature, interference, and system voltage and
frequency, where applicable. After determining the service
error, we can then calculate the measurement range. This
is the range of measurement over which the error in ser-
vice 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 measur-
ing low resistance is 0,10Ω to 99,9Ω. When checking that
a measurement does not exceed a limit, the service error
needs to be taken into account and these tables enable
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.
24
Insulation Resistance – MΩ
Limit Min. Indicated Reading
0,10 0,14
0,20 0,25
0,30 0,35
0,40 0,46
0,50 0,56
0,60 0,66
0,70 0,77
0,80 0,87
0,90 0,98
1,00 1,08
Continuity Resistance – Ω
Limit Max. Indicated Reading
0,10 0,06
0,20 0,15
0,30 0,25
0,40 0,34
0,50 0,44
0,60 0,54
0,70 0,63
0,80 0,73
0,90 0,82
1,00 0,92
Limit Min. Indicated Reading
2,00 2,12
3,00 3,16
4,00 4,20
5,00 5,24
10,00 10,8
20,00 21,2
30,00 31,6
40,00 42,0
50,00 52,4
100,00 94,0
Limit Max. Indicated Reading
2,00 1,88
3,00 2,84
4,00 3,80
5,00 4,76
10,00 9,56
20,00 18,8
30,00 28,4
40,00 38,0
50,00 47,6
100,00 92,0