14
be two screws set in opposite corners from one another on the TC filament. There are
three screws on the CC and GC filament.
3.
It may be time to change the TCD filament. These filaments are quite robust but will
occasionally fail especially when a lot of moisture is present in the sample line.
4.
Perform a quick leak check. Cover the
Sample In port
,
Chromat Exhaust
, and the
Detector Exhaust
with your fingers and observe the three different flow meters. If all
the beads fall to zero then there are no leaks. If any or all beads remain above zero,
then there is a leak somewhere from the sample in port to the exhaust. Use the
sample
flow chart
to trace the MLogger plumbing and check for any cracks, kinks, holes, or
loose poly flow fittings.
5.
Connect the 100% test gas to the Zero Air port and allow the gas to flow for about 30
seconds or more. See if the Total Gas units reach 10,000 units or close to it (9600 –
9800). If they do, then there is a leak at the IT pump. Check on the inside of the
MLogger on the
Red Side
and inspect the IT pump. Be sure all lines are connected. If
all the lines are connected then there is a leak in the pump itself. This requires the
pump to be replaced. Switch to the spare MLogger and contact the MSI office for a
new IT pump or replacement MLogger.
CCD won’t Read 100 Units When using the 1% Test Gas
1.
Check and make sure all exhaust lines are connected and free of any obstruction.
2.
There is most likely a leak somewhere around the CCD and/or TCD filament.
3.
Look at the
Red side
of MLogger and locate the CCD filament.
a.
Unplug the filament and remove the screws securing it.
b.
Check the detector and compensator of the filament to locate the o-ring for
each one. There should be only one o-ring for each component.
c.
Check the detector block for any stuck o-rings from other filaments.
4.
Check to see how many turns into the CCD Zero pot the filament is.
d.
Each Zero pot is a ten-turn pot and a new filament will generally zero 4 – 6 turns
in from the end of the pot. If the filament in question is only two counter
clockwise turns away from the end of the pot, it should be changed soon.
5.
Check the Calibration number for the CCD Voltage at 1% gas. This should be
between .9 and 1.5 Volts.
