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Figure 3: Purge inlet and outlet locations on ASM0627-09
The ideal purge gas is dry nitrogen. Alternatively, dry air from a purge gas generator can be
used. The output from this purge gas generator should have a minimum quality according to
ISO8573-1:2010 of Class 1:2:1 (dust:water:oil) or better. Keit can recommend suitable
generators that achieve this outlet air quality; contact [email protected]. Purge gas
generators may include an internal compressor or use factory-supplied compressed air with a
minimum quality of Class 4:4:4 (dust:water:oil).
NOTE
All FTIR spectrometers are very sensitive to water vapour and
carbon dioxide. Even in well-controlled environments, e.g.,
laboratories, environmental changes can be large enough to
cause significant changes in the spectrum. We STRONGLY
recommend purging the instrument at all times.
To purge the instrument:
•
Remove the blanking plug from the gas purge inlet on the instrument; this is a push fit
connector.
•
Connect a 4mm diameter gas hose to the purge inlet port.
•
Ensure the gas tube is connected to a suitable gas supply via a flow meter.
•
Adjust the total flow to 0.5 - 2 litres per minute (The pressure drop through the unit is
<1 barg).
•
Do not turn off the purge during normal operation; this will impact the instrument
’s
performance.
•
If the purge tubing is disconnected, the blanking plug must be fitted to the inlet
connection on the probe to maintain the IP rating and exclude dust.
The IRmadillo requires a stabilisation period of >12 hours once powered on and purging
started. This is to allow the internal components to reach a stable temperature and complete
purging. Once fully purged the instrument is very robust against changes in ambient
conditions, provided the purge gas supply is maintained.
2.3. How to connect data communications
Like the power cable, the IRmadillo is supplied with a permanently connected flying lead for
communication that is passed through a cable gland. You must ensure that the cables are
