50-608 Kotron Model 811 RF Point Level Sensor
16
2.0
Reference Information
This section presents an overview of the operation of
the Kotron Model 811 RF Point Level Sensor, information
on troubleshooting common problems, intrinsic safety
information, physical, functional and performance
specifications, listings of agency approvals, and a list
of recommended parts
2.1
Description
The Kotron Model 811 RF Point Level Sensor can be
utilized in liquid or bulk material applications. There are
no moving parts in contact with the medium.
2.2
Theory of Operation
As the medium in contact with the probe rises and falls,
the amount of capacitance develops between the probe and
the ground changes. This change in capacitance is convert-
ed into level. When the level (capacitance) reaches a
desired amount, the relay will change state.
2.3
Troubleshooting
2.3.1 No Signal with Level Change
1. Check power and control circuit wiring.
2. Check DIP switch positions.
3. Check Calibration.
4. Check for proper ground reference particularly in
non-metal tanks.
2.3.2 Probe
Caution:
When an insulated probe is used in a hazardous and/or
abrasive medium, the probe should be inspected periodi-
cally for nicks, cuts or abrasions which may ruin the
integrity of the insulation. In the event that wear is found –
replace the probe or consult the factory for further instruc-
tions. This procedure is critical in vessels containing
hazardous media.
To check for a malfunctioning sensing probe:
1. Remove the white probe lead from the sensing probe and
isolate it from the ground.
2. Connect an ohmmeter between the sensing probe terminal
and ground. (i.e., stainless steel probe nut or housing base)
