50
9-3-5 Correction Required When an Extension Cable was Used
Indoor measurement seldom requires an extension cable. By contrast, for outdoor measurement the
DPM-900/950 series has to be remote from a measuring point on occasions. If such is the case, place a
bridge box nearby a measuring point, then connect a bridge box to the DPM-900/950 series using an
extension cable. Note that a measurement thus obtained inevitably contains an error due to an extension
cable. The longer an extension cable is used, the larger a measurement error grows. In order to remove this
error, multiply a measured value by a suitable correction factor stated in the following table.
In addition, this correction method will not be free from a certain amount of error inducible to the kind of
an extension cable and the ambient temperature.
Correction factor when using the extension cable with the DPM-911/951
Extension Cable
Bridge Resistance
5 m
25 m
50 m
75 m
100 m
200 m
120 ohm
1.003
1.015
1.030
1.046
1.060
1.120
350 ohm
1.002
1.005
1.009
1.013
1.017
1.032
Correction factor when using the extension cable with the DPM-912/952
Extension Cable
Bridge Resistance
5 m
25 m
50 m
75 m
100 m
200 m
120 ohm
1.003
1.017
1.034
1.052
1.069
1.151
350 ohm
1.002
1.009
1.015
1.023
1.031
1.070
Correction factor when using the extension cable with the DPM-913
Extension Cable
Bridge Resistance
5 m
25 m
50 m
75 m
100 m
200 m
120 ohm
1.006
1.025
1.046
1.081
1.112
1.326
350 ohm
1.007
1.033
1.067
1.103
1.138
1.309
Shown in the above tables are correction factors applicable to the KYOWA extension cable (0.5 mm
2
,
4-conductor shielded cabtire cable) that is described in “6-3 EXTENSION CABLE N.”