Installation, Operation, & Maintenance Instructions
IOM J500.35
2021.04
JMT
● +1.440.572.1500
19
4.2.10 Alarms
There are four possible alarm conditions available in the event
that the float is not detected.
3.5 mA
– Current output will go to 3.5 mA if a float is not
detected.
21.0 mA
– Current output will go to 21.0 mA if a float is
not detected.
Hold last then 3.5 mA
– Current output will go to 3.5 mA
if a float is not detected after waiting a user specified
number of second (Up to 1000 seconds).
Hold last then 21.0 mA
– Current output will go to 21.0
mA if a float is not detected after waiting a user specified
number of seconds (Up to 1000 seconds).
4.2.11 Filters
Several filters are automatically used by the JMT to prevent erroneous signal measurement. These filters
may be adjusted as described in the
Measurement Troubleshooting
section in
Troubleshooting.
There is no need to do so under normal operation.
Rate of Change Filter
The
Rate of Change Filter
is designed to remove random noise
the sensor may detect from vibrations or electromagnetic
interference. The operating principle is that there is a maximum
speed at which the float can move, meaning the measured level
can only change so much between each measurement. Each
measurement is compared to the one before it, and if a signal is
detected outside what this filter would allow it is ignored,
allowing the true signal from the float to be detected.
The
Rate of Change Filter
is set with both a distance
measurement, and time requirement.