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KAHN INSTRUMENTS, INC.
885 Wells Road, Wethersfield, CT 06109
Tel: 860-529-8643; Fax: 860-529-1895
E-mail: [email protected]
www.kahn.com
Care should be taken with gas mixtures containing other potentially condensable
components in addition to water vapor to ensure that only water can condense onto the
cooled mirror surface.
The Series 4000 Sensor Unit will not contaminate high purity gases. Components which
are likely to out -gas (epoxy, most plastics etc.) are not used in the manufacture of the
sensor. Therefore, the instrument is safe for use in critical semiconductor and fiber-optic
applications.
While the Series 4000 Sensor is designed to be operated at atmospheric pressure, each
sensor is factory tested to a sample gas pressure of 10 psig before any calibration work
is performed. In its standard form, the sensor unit is not suitable for measuring samples
below atmospheric pressure.
4.4
Operating the Hygrometer
4.4.1 General
Use the following instructions with reference to the front panel of the Series 4000
Integrale
Monitor Unit, and the functional descriptions provided in Section 2.
Check that the sensor optics are clean as described in section 6. If the optional
microscope is not being used ensure that the black blanking plug is screwed into the
microscope fitting on the front of the Monitor Unit to prevent stray light from interfering
with the optical detection system. Set the sample gas flow-rate to between 50 and 200
cm
3
/min. (0.05 and 0.2 l/min.) as indicated on the Monitor Unit front panel flow meter.
The temperature measurement and %RH calculations within the instrument are fully
automatic and do not require any user adjustment or maintenance.
When the Monitor Unit is switched on a red neon illuminates in the power switch and the
digital display should illuminate.
4.4.2 Operating the Automatic Balance Compensation System
Upon first switching ON the instrument, press the INITIATE button to manually initiate a
balance cycle. The dual colored ABC STATUS (LED) will glow green. Note: it may glow
amber if the Dewpoint Meter is not already balanced or, flash amber for an instant at the
start of a balance cycle until dew or frost, if present, on the cooled mirror surface is
evaporated.
The instrument will now perform a balance cycle to compensate the ABC system for the
current level of contamination of the optical system.
