Optional Equipment
Internal Zero Air Scrubber
9-4
Model 48
i
Instruction Manual
Thermo Fisher Scientific
8.
Use the screwdriver to adjust the Span potentiometer RV2 such that
the O
2
reading indicates the correct percent concentration. For
example, 25% oxygen span gas should be set to produce a measurement
of 25.00%.
9.
Replace the cover, wait 30 minutes for the instrument to stabilize, and
repeat the four steps in the “Calibration” procedure.
The internal air scrubber is mounted inside the instrument and provides a
source of zero air.
The filter wheel purge option includes a housing attached between the
optical bench and the motor plate (
Figure 9–2
). It surrounds the gas
correlation wheel and allows purging the area around the gas correlation
wheel with a gas other than that present in the local atmosphere. This
option increases reliability in the presence of contaminants that could
interfere with the analytical process.
Figure 9–2.
Purge Housing Assembly
Internal Zero Air
Scrubber
Filter Wheel Purge
Purge Wheel Housing
Motor Plate