M.C. MILLER SRM Test Box User manual

MAN470 March 1, 2022
1
Updated March 1, 2022
SRM Text Box Instructions
It is tool to help the field technician diagnose problems encountered when
performing a soil resistivity survey by confirming the soil resistivity meter is
performing properly. By ruling out the meter as a source of an error, the
technician can then troubleshoot the external connections or associated cables to
determine the cause.
Note: All resistance values are ±1.0%
Connections to the 400A / 400D Soil Resistivity Meter (SRM):
Using known good test leads, connect from the resistivity meter to the test box as
follows: P1 to P1, P2 to P2, C1 to C1 and C2 to C2 as per Figure 1 below. This
simulates a Wenner 4 pin resistivity test.
Set the switch on the test box to the desired Ohms position and take a reading
with the SRM. The reading on the SRM should be very close to that indicated by
the test box setting. If a great difference is noted, the meter should be returned
to M. C. Miller Co. for repair and re-certification.
If a 2 pin test is desired, connect the meter’s P1 and P2 leads to P1 and P2
respectively to the test box and place jumper leads on the meter from P1 to C1
and P2 to C2 as per Figure 2 below.

MAN470 March 1, 2022
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Updated March 1, 2022
In addition to the selectable ranges shown on the label, it is possible to simulate tests up to 30KΩ
byconnecting themeterP1,P2 leadstothetestboxC1, C2jacksandplacing jumpersonthe
meterterminalsbetweenC1,P1andasecond jumperleadbetweenP2 ,C2 asperFigure3
below.
With 0Ω selected on the test box a 2 wire test will be performed at 20KΩ and selecting 10K will
allow a 2 wire test at 30KΩ.

MAN470 March 1, 2022
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Updated March 1, 2022

MAN470 March 1, 2022
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Updated March 1, 2022
Notes: