Check Of The Eo -Sensor - Emerson ROSEMOUNT Analytical NGA 2000 Instruction Manual

Instruction Manual
90002929
07/2006
18.2 Check of the EO
Exchange the sensor, if the voltage is less than 70 % of the initially output voltage.
The check requires a digital voltmeter (DVM) with a range of 2 V DC.
Remove front panel (see 15.).
Switch On the analyzer (see Section 6.).
Admit ambient air to the analyzer (approx. 21 Vol. - O
Connect the DVM to the measuring points
Tp 1 (Signal) and Tp 2 ( ⊥ ⊥ ⊥ ⊥ ⊥ ) of the PCB OXS, mounted directly at the connection block
(Fig. 18-1, see also Fig. 18-2, 1-3, 1-16a and 1-17).
The measuring signal should be into a range of 700 mV DC to 1000 mV DC.
Note !
If the measuring value is lower than 700 mV at gas flow with ambient air, the sensor is consumed.
Exchange the sensor.
Emerson Process Management GmbH & Co. OHG
CHECK AND REPLACEMENT OF ELECTROCHEMICAL OXYGEN SENSOR
-Sensor
2
Tp 1
Potentiometer "R4"
Fig. 18-1: PCB "OXS", assembled, horizontal projection
NGA 2000 MLT Hardware
).
2
Tp 2
CHECK OF EO -SENSOR
2
18 - 3