Preventive Maintenance
IR Source Replacement
Thermo Fisher Scientific
Model 48
i
Instruction Manual
5-3
3.
Carefully clean each mirror using a cotton swab and methanol. Rinse
with distilled or deionized water. Dry by blowing clean dry air over the
mirror.
4.
Reassemble following the above procedure in reverse. It is not necessary
to realign any mirror following cleaning.
5.
Calibrate the instrument. See the “
Calibration
” chapter in this manual.
The IR source control system has been designed to operate the wire wound
resistor IR source conservatively in order to increase its life. Nevertheless,
the IR source does have a finite life. Since the IR source is relatively
inexpensive and easily replaced, it is recommended that the IR source be
replaced after one year of continuous use. This will prevent loss of data due
to IR source failure. If an IR source is to be replaced on an as needed basis,
it should be replaced when:
●
There is no light output
●
After cleaning the optics, the IR light intensities remain below 100,000
Hz
It is not necessary to recalibrate the Model 48
i
after replacing the IR source
since it is a ratio instrument, and replacing the IR source does not affect the
calibration.
Use the following procedure to inspect and clean the fan filter (
Figure 5–
1
).
1.
Remove the fan guard from the fan and remove the filter.
2.
Flush the filter with warm water and let dry (a clean, oil-free purge will
help the drying process) or blow the filter clean with compressed air.
3.
Re-install the filter and fan guard.
IR Source
Replacement
Fan Filter Inspection
and Cleaning
