Ion Science Tiger Select - Manual (Page 12)

TIGER MANUAL Ion Science Ltd
Page 12 of 20
Unrivalled Detection. www.ionscience.com
Calibration
Calibration type
Tiger Select has 3 calibration options:-
1. Factory calibration:
This calibration is only used in normal running mode so is not used in TAC or Select
mode. Factory Calibration is carried out at Ion Science during manufacture. This can
be selected by the user but cannot be changed. Factory calibration should be
carried out annually by Ion Science Ltd or an authorised service centre only.
2. Custom calibration: This calibration is used in normal running mode and TAC mode. Custom Calibration
allows the user to calibrate the Tiger on alternative gases and using alternative
concentrations.
3. Select calibration: The Tiger Select has a separate calibration set aside for tube mode. Please note
that a tube calibration must be carried out before access to tube mode is allowed.
[JB3]
Please see page 13.
The Select calibration settings can be adjusted on the configuration screen in Tiger PC. Benzene gas must
be selected when using a Benzene pre filter however the calibration gas concentration can be adjusted.
Frequency of calibration
The frequency at which the Tiger Select is calibrated can vary considerably. Changes in environmental
conditions, frequency of use or the gas being detected can all affect the accuracy of the instrument. Ion
Science suggests customers carry out weekly calibrations but then extend this time as confidence is gained
and any environmental effects identified.
Tiger Select should also be calibrated for the following reasons:-
* When a new batch of pre-filter tubes are used. Batch numbers can
be found on the end of the tube carton.
* After servicing
Demand and flow regulators
The Tiger Select can be calibrated using either a flow regulator or a demand regulator.
Demand regulators rely on the instrument pump drawing the sample from the gas bottle. These regulators
supply exactly the amount of gas necessary to calibrate so are economical. They also avoid the risk of
leaving the gas bottle switched on. Demand regulators however rely on the host instruments pump to draw
the sample which causes a slight partial vacuum of between -7 to -10 mbar. For an accurate calibration the
entire pneumatic system must be completely sealed.
Flow regulators supply a fixed amount of gas which should exceed what the
instrument requires. A little gas is lost and the instrument takes what it needs.
The Tiger Select requires 250 cc/min so flow regulators of 300 cc/min
(0.3Lr/min) is advised. Being a flood leak the sample has the benefit of being
matched to ambient air pressure.
Instrument from Flow regulator