Specifications

Calibration H25-IR
24 Instruction 3015-4342
MUST BE ZERO TO CALIBRATE” will appear. If necessary, press the ZERO button to zero the gas
display before pressing 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, press the ESC key to 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.
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 2.5.7 PCHK Mode), then a pressure check is performed prior to the display of the Data Display
screen.
NOTE: After calibration the instrument is automatically placed into its Search mode.
3.4 CAL Factor
The factory default CAL Factor of 1.000 will provide the level of accuracy as stated in Section 6 Troubleshooting
for all gases.
The CAL Factor can be changed for the following two reasons:
 Allow the instrument’s internal leak source to be used to calibrate the instrument,
regardless of the gas being measured
 Improve the accuracy of ppm measurements
Leak-rate accuracy can be maintained by periodically calibrating the instrument on the gas being measured. If
the instrument’s internal calibration gas is the same as the gas being measured, then it is a simple matter of
calibrating the instrument using the internal leak source. When measuring a gas that is not the same as the
instrument’s internal calibration gas, then there are two options for maintaining accuracy. The instrument can
either be calibrated using an external leak source, or the CAL Factor can be adjusted to make the internal leak
source simulate the gas being measured as described in Section 3.4.1.
The CAL Factor can also be used to improve the accuracy of ppm measurements as described in Section 3.4.2.
Oz/yr
R134A
SETUP
SM SRCH
Oz/yr
R134A
SETUP
EXT CAL
0.00
0.89
TARGET
O/YR
R134A
MEASURED
O/YR
0.89
0.89
Oz/yr
R134A
SETUP
EXT CAL
TARGET
OZ/YR
R134A
MEASURED
OZ/YR