Bacharach H25-IR - Manual (Page 29)

H25-IR Calibration
Instruction 3015-4342 23
2. Press the front panel CAL button to display the Calibration screen. Note that the display must be
reading a leak rate of “0.00” when the CAL button is pressed; otherwise, the message “LEAK RATE
MUST BE ZERO TO CALIBRATE” will appear. If necessary, press the ZERO button to zero the display
before pressing CAL.
3. Ensure that the instrument is set up for internal calibration as indicated by “INT CAL” being displayed at
the bottom-right of the display. If “EXT CAL” (external calibration) is displayed, press the ESC key to
perform the procedure in Section 3.1 Selecting Internal or External Calibration and set the Cal Type to
Internal.
4. Insert the probe tip into the CAL Port within 10 seconds after
pressing the CAL button. Be sure that the probe tip makes
contact with the spring switch. At this time the calibration
process should automatically start.
The top number of the Calibration screen shows the “target”
value (leak source rate), while the bottom number shows the
current measured value. Keep the probe tip firmly against
the back of the port for the duration of the calibration
process, during which time the instrument is calibrated at
both a high and low flow rate.
If the probe tip looses contact with the spring switch before the
calibration process completes, the message “CAL ABORTED” is
displayed. At this time press any key to retain the previous
calibration curve and return to the Data Display screen.
5. After a successful calibration the new calibration data is saved and
the message “CAL OK” followed by “WITHDRAW PROBE FROM
LEAK SOURCE” will appear.
6. Withdrawing the probe causes the display to switch back to the
Data Display screen. Note, however, if the PCHK Mode is set to
AUTO (refer to Section 2.5.7 PCHK Mode), then a pressure check
is performed prior to the display of the Data Display screen.
NOTE: After being calibrated the instrument is automatically placed
into its Search mode.
3.3 External Calibration
External calibration uses a customer supplied leak source that matches the gas to be monitored. Properties of
the leak source must be entered by the operator using the EXT RATE and EXT GAS TYPE functions as
described in Section 3.1.2 External Calibration Selection and Setup. The EXT RATE entry is the number
displayed as the “target” value during calibration.
IMPORTANT! The operator is responsible for ensuring that the external leak-rate value has been corrected
for daily changes in ambient temperature and pressure at the time of calibration. It is also the operator’s
responsibility to ensure that a good calibration has been performed.
1. Turn ON instrument and allow it to complete its 120 second warm-up.
2. Press the front panel CAL button to display the Calibration screen. Note that the display must be
reading a leak rate of “0.00” when the CAL button is pressed; otherwise, the message “LEAK RATE
CAL
OK
Oz/yr
R134A
SETUP
INT CAL
WITHDRAW PROBE
FROM LEAK
SOURCE
Oz/yr
R134A
SETUP
INT CAL
Oz/yr
R134A
SETUP
SM SRCH
0.00
Oz/yr
R134A
SETUP
INT CAL
TARGET
O/YR
R134A
MEASURED
O/YR 0.89
Oz/yr
R134A
SETUP
INT CAL
0.89 TARGET
O/YR
R134A
MEASURED
O/YR
INSERT
PROBE
PCHK