Technical User Guide
DOL 51
5
5 Functions
5.6
7.2
8.8
10.4
13.6
15.2
16.8
18.4
NH3
Figure 4: Functional graph.
6 LED indication
LED indication
Sensor status
Action
YELLOW flashing
slowly
Incorrect electrical supply or inter-
rupted supply.
Check installation for cable break. Check the
power supply unit of the control unit. Check elec-
tric voltage in the junction box or at the sensor el-
ement with a multimeter.
Short circuit in supply cable.
Check installation for short circuit.
Overvoltage or undervoltage at the
DOL 51 housing.
Check electric voltage at the DOL 51 housing
with a multimeter.
Incorrect voltage (e.g. 230 V AC)
applied, electronics damaged.
Replace the DOL 51 housing.
DOL 51 housing is defective.
Replace the DOL 51 housing, contact the sup-
plier.
Alternating GREEN
and YELLOW
Sensor is warming up to be ready
for measurements, signal level 0V
and 4mA.
No activity. Flashing stops after max. 30 minutes.
Constant GREEN
Normal operation.
GREEN flashing
quickly
The ammonia concentration is be-
tween 40-60 ppm, which is used to
test the sensor. The sensor is
working, but it works as if it is in
test mode.
No activity. Flashing stops after max. 5 minutes.
Constant YELLOW
Internal fault detected by electron-
ics, signal level 0 V.
Replace the DOL 51 housing.
YELLOW flashing
quickly
There is very little ammonia in the
livestock house – under 5 ppm, the
sensor output is 0V.
Replace the sensor element, if the fault continues
for more than one day.
