Fir 1, 2, 3 & 5000
Ion Science Lt d
Ion Science L td
Page 19 of 53
Instrument Menu
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Calibration (1, 2, 3 & 5)
'Factory calibration' is set by Ion Science during
instrument manufacture. 'Custom calibration' can be
set by the instrument user.
General description
Due to the linear output of the Ion Science PID detector cell, Fir instruments only require a two-
point calibration. The Fir scales its linear output across a 'Zero' level (clean air reference) and the
'Span' (a user defined gas concentration).
Factory Calibration
When 'Factory' calibration is selected the Fir will measure according to the factory set fixed points
and display the selected signal reading according to this reference.
'Factory' calibration offers a constantly repeatable reference, however prolonged use may mean these
reference points become less accurate. It is recommended that the Fir be returned to Ion Science
once a year for an annual calibration and service.
Custom calibration
When 'Custom Calibration' is selected a 'Zero' and 'Span' can be set by the user. This allows the user to
calibrate the Fir PID to an alternative gas (other than Isobutylene). Ion Science provide a
Calibration Kit accessory (Part number A-845213) which is recommended for use with Fir, however
other gases specific to your needs can also be used.
If performing a custom calibration using the Ion Science Calibration Kit accessory you will need you use the
Cal Adaptor supplied with your Fir in the Cal Kit sample box. WARNING: when fitting the Cal
adaptor onto the gas tube (part of the Calibration kit) ensure that the small breather hole of the Cal adaptor
is not covered as this will cause the instruments internal pump to be damaged beyond repair. Failure to
adhere to this warning will invalidate your warranty should your instrument pump become damaged.
In order to carry out a custom calibration the appropriate parameters need to be set via the 1stPC software
and downloaded to the Fir instrument. Please see the Fir software calibration section
(page 28) for details on how this can be achieved. Once these parameters have been set, a custom
calibration can be completed (please see recommended procedure below.)
Ion Science suggests custom calibrating when detection in ppb is required, or when high accuracy is needed
for a specific gas other than Isobutylene.
Factory Custom
