Vaisala DMT143 - Trouble Shooting; Analog Output or Display does not match expected value

Procedure Instruction 5(16)
Field Tech Manual for DMT143-series
2018-04-06
Vaisala Instruments
Trouble Shooting
4.1 Analog Output or Display does not match expected value
Step 1.) Check the label on transmitter, to verify the transmitter configuration of
parameters, engineering units and scale for appropriate channel.
Step 2.) With USB Service Cable, force analog outputs to 0% and 100% of scale to
verify reading on the control display, PLC, chart recorder, data logger or analog
receiving device displays correct scale.
Analog Output Tests
Using USB Service Cable and Service Port: ITEST Command
With the PuTTY serial program, use the ATEST command to test the operation of the analog outputs. The
ATEST command forces the analog outputs to entered values. The analog outputs remain at these values
until you enter the command ATEST without parameters or reset the transmitter
Examples:
atest
17.585 24000
atest 4
4.000 5447
atest 20
20.000 27298
atest
17.583 27298
4.2 Measurement Reading bounces around
If the measurement reading jumps around, this can be caused by several factors. Factors include unstable
process, varying control conditions, wrong location for sensor placement, ground loops, and leaks in
system allowing environmental conditions to affect process.
First, check the location of the installed sensor is not obstructed intermittently or insulated properly from
ambient fluctuations.