Veris Technologies 3150 Soil EC Mapping System - Trouble-shooting - Manual (Page 3)

Procedure #2: 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 EC Surveyor to the disk blade. Think of each coulter-electrode and its wire
path as
a ‗channel‘. On a 3100 and 3150, there are 6 signal channels that must be clear
and isolated from each other (4 on a 2000XA). You will first test the complete pathway for
each channel
—each coulter-electrode. One easy-to-take reading for each channel tests
the cable, wiring harness, and each coulter-electrode and disk blade. 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 (part #10759) 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.
Figure 2.1