Bacharach H25-IR manual External Calibration

Calibration H25-IR

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 MUST BE ZERO TO CALIBRATE” will appear. If necessary, press the ZERO button to zero the gas display before pressing CAL.

0.89TARGET Oz/yr

O/YR R134A

R134A

0.00MEASURED SETUP

O/YR EXT CAL

3.Ensure that the instrument is set up for “EXT CAL” (external calibration) as indicated at the bottom-right of the display. If “INT CAL” (internal calibration) is displayed, perform the procedure in Section 3.1 Selecting Internal or External Calibration and set the Cal Type to External.

4.Insert probe tip into the Calibration Port of the external leak source.

5.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 inserted in the Calibration Port for the duration of the calibration process, during which time the instrument performs a calibration at both a high and low flow rate.

0.89

0.89

TARGET	Oz/yr
OZ/YR	R134A
R134A
	SETUP
MEASURED
OZ/YR	EXT CAL

6.After the calibration cycle is complete, the new calibration data is saved and the display automatically switches back to the Data Display screen. Note, however, if the PCHK Mode is set to AUTO (refer to Section 2.4.7 PCHK Mode), then a pressure check is performed prior to the display of the Data Display screen.

Oz/yr

R134A

SETUP

SM SRCH

NOTE: After calibration the instrument is automatically placed into its Search mode.

24 Instruction 3015-4342