25
4.
After
"End"
appears on the display and the instrument beeps,
calibrate without
moving the selector switch from the TRACK GAS position.
Insert the tip of the
standard probe partially into the outlet port of the gas dispenser or, if a manual
calibration apparatus (for example, Part No. PCA-302) is used, attach the detector's
water-block filter to the threaded hose barb (TB-512) with the regulator's valve off
and wait for
"bloc".
5.
After
"bloc"
appears on the display, push the probe completely into the dispenser
port. The
"bloc"
display will be replaced by
"go"
and the instrument will calibrate
the catalytic combustion and CO sensors.
If a manual apparatus is used, open the flow regulator's valve and observe
"go"
on
the display.
The detector's display will show
"GAS 2"
while the catalytic combustion sensor is
being re-calibrated and
"CO"
when the CO sensor is being re-calibrated.
6.
After calibration, the detector will show
"CAL"
and the instrument will beep briefly.
Remove the probe from the gas outlet. Replace the black #4-40 screw and the
instrument is ready for use.
Note:
During SCAL calibration, the selector switch remains in the TRACK GAS
position. After calibration is complete and
"CAL"
is displayed, the selector
switch must be placed at the OFF position to return the monitor to a normal
operating mode.
CAUTION:
SCAL calibration presupposes and depends on using Bascom-Turner's
calibration gas (Part No. MC-620). Do not use a gas of a different composition
for automatic calibration. If some other gas is used, calibration should be
carried out manually.
Error Codes during SCAL
. The only error code that may appear during SCAL
calibration is
"nogo"
(no go). This code, which denotes that SCAL calibration cannot proceed,
may appear in the following circumstances:
i)
More than 30 seconds elapse between the
"go"
display and the introduction of
calibration gas. If this is the case, wait for an additional period up to 60 seconds,
with gas flowing through the instrument. The
"nogo"
display will be replaced by
"CAL"
when the sensors are calibrated.
ii)
A sensor is not sufficiently stable for calibration to proceed normally or the gas
composition is varying with time. This last condition may hold if the calibration
system has not been purged (e.g., first calibration of the day). If this is the case, wait
for an additional period of up to 60 seconds with gas flowing through the instrument.
If response is stable, the monitor will be calibrated and
"CAL"
will appear on the
display. If the instability persists, the
"nogo"
display will persist. The instrument
must then be tested manually and the cause of the malfunction corrected.
iii)
The monitor’s gain is set too high by a previous manual calibration. The unit must
be calibrated manually.
