Page 11
11.0
Calibration
The GAS CHECK SF6 is unique in that completely separate values are stored for each of
the display modes. This means that if you want to measure ppm or gm/yr these values
must be calibrated before use. Calibration follows the same easy routine as with cc/sec
calibration using the
Portable Reference Leak
. Regular calibration further improves the
precision of measurement over the standard (factory set) calibration.
For cc/sec (volume loss over time mode) You will need the Portable Reference Leak
(PRL), supplied as an option with the instrument and available from Ion Science Ltd.
The leak rate will be approximately 5x10-6cc/sec (5 E-6cc/sec)
Press Calibration. The screen now asks you to enter (or confirm) the leak rate of the PRL
(or gas concentration when in ppm mode). If this is to be changed, then use the keypad
to enter the SAME leak rate as printed on the PRL.
As long as the same PRL / gas concentration is used, this value needs to be entered only
once
.
Just press RETURN to confirm it each time you make a calibration.
On pressing
RETURN
the calibration process begins.
Background Air is measured first, which takes 4 seconds. A time bar is displayed along
with an audible ‘bleep’. The display then instructs the operator to put the probe to the
reference leak. When this is done, the final calibration step begins automatically and
takes 6 seconds.
During this time, it is important to hold the probe accurately in the reference leak,
otherwise an incorrect calibration may occur.
Should the leak be missed or the probe removed by mistake, just move the probe off the
leak. The time bar is then reset, and the process can be re started.
When calibration is complete, the instrument returns to normal mode. Now check the
portable reference leak, which should be the same reading (+/-5%). Repeat the
calibration if necessary, and remember to accurately hold the probe in the leak.
The Exit button can be used to abort calibration at any time. The original calibration
factor then remains unchanged.
11.1
Set clock
The clock keeps time even while the instrument is off. Adjustment may be necessary for
the following: Summer / winter time changeover, Different time zone
Normal long term adjustment.
If the battery has been disconnected.
Should this happen, the instrument automatically
opens the set date/time screen after power on.
This is quite straightforward; use the -/+ pads to change and when correct press Exit.
