Testing Electrical Continuity - Veris U3 Operating Instructions Manual

Procedure #3: Testing Electrical Continuity
Perform this test daily or every 20 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 a
U3000, 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 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 # 223707) 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 3.1
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.
6-3
Pub# OM20-U3-pH