Erratic Readings; Zero Readings When Pressurized; Grounding Issues - Seametrics LevelSCOUT Instructions Manual

LEVELSCOUT INSTR
TROUBLESHOOTING

Erratic Readings

Erratic readings can be caused by a poor connection, damaged cable, moisture in the unit,
or a damaged transmitter. In most cases, erratic readings are due to moisture getting
into the system. The first thing to check is the connection. Look for moisture between
contacts or a loose or broken wire. Next, check the cable for cracking or fraying. If
the connections and cable appear OK, but the readings are still erratic, the transmitter
may be damaged. Contact Seametrics for evaluation and repair. Erratic and erroneous
readings can also occur due to improper grounding. See Grounding Issues, below.

Zero Readings When Pressurized

Continuous zero readings are usually caused by an open circuit which may
indicate a broken cable, a bad connection, or possibly a damaged transmitter.
Check the connector to see if a wire has become loose or if the cable has been cut.
If damage is not readily apparent, contact Seametrics for evaluation and repair.

Grounding Issues

It is commonly known that when using electronic equipment, both personnel and
equipment need to be protected from high power spikes that may be caused by lightning,
power line surges, or faulty equipment. Without a proper grounding system, a power
spike will find the path of least resistance to earth ground – whether that path is through
sensitive electronic equipment or the person operating the equipment. In order to ensure
safety and prevent equipment damage, a grounding system must be used to provide a
low resistance path to ground.
When using several pieces of interconnected equipment, each of which may have its own
ground, problems with noise, signal interference, and erroneous readings may be noted.
This is caused by a condition known as a Ground Loop. Because of natural resistance in
the earth between the grounding points, current can flow between the points, creating an
unexpected voltage difference and resulting erroneous readings.
The single most important step in minimizing a ground loop is to tie all equipment
(sensors, dataloggers, external power sources, and any other associated equipment) to
a single common grounding point. Seametrics recommends connecting the shield to
ground at the connector end.
Seametrics • 253.872.0284 Page 34 seametrics.com