
dol-sensors a/s Hedelund 4, Glyngøre 7870 Roslev Denmark Tlf. +45 72 17 58 88 Fax +45 72 17 59 59 www.dol-sensors.com
EN–TECHNICAL USER GUIDE
TROUBLESHOOTING
Contact the supplier in case of a damaged DOL 53.
No measured value at the control
unit.
Electrical connection faulty or interrupted.
Check installation for cable break.
DOL 53 aligned incorrectly, not vertical.
Install DOL 53 in accordance with assembly
instructions, vertical ±30°.
Sensor element faulty or used up.
Incorrect measured value at the
control unit.
Check sensitivity with test gas.
Unexpected measured value at the
control unit.
Brief interference pulses <5 seconds.
Interference caused by electrical equipment, e.g.
lighting, fans or heaters; identify device and
suppress interference.
Dynamic signal fluctuations with a period of more
than 5 seconds can arise from turbulence with fresh
air.
Not activity, continue to monitor.
DOL 53 was cleaned with water, condensation.
Wipe DOL 53 dry with a paper towel.
Electrical supply faulty or interrupted.
Check installation for cable break. Check operation
of the power supply unit of the control unit. Check
electric voltage in the junction box or at the sensing
head with a multi-meter.
Short circuit in supply cable.
Check installation for short circuit.
Overvoltage or undervoltage at the sensing head.
Check operation of the power supply unit of the
control unit: Check electric voltage at the sensing
head with a multi-meter.
Incorrect voltage (e.g. 230 V AC) applied,
electronics damaged.
Replace the sensing head.
Replace the sensing head, contact supplier.
Alternating green and yellow
Sensor is warning up to be ready for
measurements, signal level 0 V.
No activity, flashing stops after max. 30 minutes.
Concentration measurement in the test window 40
ppm to 60 ppm, result of a test with 50 ppm test
gas.
No activity, flashing stops after max. 5 minutes.
Internal fault detected by electronics, signal level 0
V.
Replace the sensing head.
Measured concentration below - 5 ppm, below the
measuring range, signal level 0 V.
If the fault continues for more than 1 day replace
sensor.
Measured concentration above 105 ppm outside
the measuring range.
Ventilate with fresh air.
Alternating green and yellow
Age monitoring, sensor older than 3 years, service
life expired, see date on sensor rating plate.