PerkinElmer AVIO 500, Customer Hardware And Service Manual

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Spectrometer
The optics are mounted to modules which are secured to the aluminum tub-like
enclosure.
Nitrogen is used to purge the optical system during operation to remove oxygen
and moisture and keep the environment dry. The nitrogen purge also improves
sensitivity for elements with wavelengths below 190 nm, particularly aluminum at
167 nm.
Detector Cooling and Purging
The detector is housed in an airtight enclosure and cooled to minus 40
0
C to
minimize dark current noise. The cooling system uses a solid-state thermoelectric
cooler with a water-cooled copper heat sink. A temperature sensor on the detector
monitors the temperature of the detector to make sure it is properly cooled. To
detect any water leaks, there is a float sensor. If the sensor detects that water is
collecting, the cooling water is turned off and the spectrometer automatically shuts
down.
To avoid condensation on the detector, filtered argon is used to purge the detector
housing. A flow sensor on the argon input line monitors argon flows.
Caution
Make sure that the required purity of the argon gas is 99.996% pure
otherwise the detector
will be damaged.