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Procedure #3: Testing Electrical Continuity
Perform this test daily or every 10 hours of data collection to ensure you are obtaining reliable data, and
whenever EC data is questionable.
The purpose of this test is to insure that each coulter-electrode has an uninterrupted signal path from the V-
Sense controller to the disk blade. Think of each coulter-electrode and its wire path as a 'channel'. On an
iScan, there are 4 signal channels that must be clear and isolated from one another. You will first test the
complete pathway for each channel—each electrode. One easy-to-take reading for each channel tests the
cable, wiring harness, and each electrode. If no problems surface during this test, there is no need to test
individual components. This test should take only a couple of minutes to perform.
To perform this test, you will need the EC Signal Test Box and an ohmmeter (sometimes referred to as a
multi-meter or voltmeter). Make sure the meter is set to ohms, Ω. If a range of ohms is available, choose
the lowest setting--ohms rather than kilo or mega ohms. If unfamiliar with 'ohming-out' or resistance testing,
make a few trial tests before performing the Veris signal test procedure. Touching the meter leads together
will display a zero resistance reading, touching two places on the same piece of metal will produce a nearly
zero reading, touching nothing will produce an OL (overload or over limit) reading—meaning complete
resistance, and no continuity.
Remove the signal cable from the V-Sense Controller and connect it to the terminal on the test box. This
cable attaches to the signal cable end and allows you to position the Signal Test Box in close proximity to
the coulter-electrodes.
Firmly press one lead of the ohmmeter to the #1
electrode—front coulter blade edge and the other
lead to the #1 terminal on the test box (I series pins
are labeled below the terminals). Maintain firm
pressure on the ohmmeter lead touching the disk
blade. A reading of less than 2 ohms is normal.
Rotate blade ¼ of a turn back and forth as you view
the ohmmeter. Any jump in the readings above 2
ohms indicates a problem.
Disconnect EC signal
cable from V-Sense
controller and connect to
test box
Figure 3.1
Figure 3.2
6-3
Pub# OM22-iScan EC-OM
Terminal pins for
iScan are labeled
below the pins
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