ELTRA ONH-2000 - Page 11

 2002 by ELTRA GmbH Germany – January 2002 – Service Manual OH 900 / ON 900 / ONH 2000
1.1-3
TC-cell check displays ++++ or -9.99 ( see 2 .12 )
If the test of the TC-cell still shows ++++ or - 9.99 after 5 minutes of carrier gas flow,
check the flow rates first ( see 2 .12) .
If they are OK, watch the zero baseline of the nitrogen channels and adjust them if
necessary.
If it is not possible to get a straight baseline by using the jumper and trimmer ( see 2 .12 ),
check the resistance of the thermistors.
Unplug the connector of the TC-cell and open the metal block of the TC-cell.
Connect an ohmmeter across each thermistor ( don't open any connection ).
The expected reading should be approximately 5-6 KOhm.
In case you should measure more than 14 KOhm across one specific thermistor, then that
thermistor is faulty and must be replaced.
CAUTION :
The thermistor is a small part inside of the glass ball, in the middle of the wire.
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1-1 -3