Bacharach H25-IR - Manual (Page 48)

Parts &Service H25-IR
42 Instruction 3015-4342
move the blinking cursor across the screen to highlight the digit to be modified, and then using the Up and
Down buttons to modify that digit. Press ENT to save the new ambient pressure value.
Tip: To convert inHg into PSIA, multiply inHg by 0.491. For example: 30.00 inHg x 0.491 = 14.73 PSIA.
5.2.6.2 Flow Rate Sensor Calibration Screen (Factory Calibration)
Set the default factory calibration flow and pressure drop values by first performing an internal calibration as
described in Section 3.2 Internal Calibration.
INT: Flow rate in moles/minute for both the Search and Measure modes after performing a calibration using the
internal leak source, along with showing the manifold’s pressure drop.
FAC: Flow rate and pressure drop values that are currently stored as the default factory calibration values.
These values are used to validate calibrations performed by the operator. A calibration error will occur if the
operator’s calibration and factory values differ by more than 20%.
Press ENT to store the internal calibration numbers as factory values. These are the calibration values that are
reset when RESTORE FACTORY CAL is selected from the CAL Data menu (refer to Section 3.5 Restoring
Factory Calibration).
5.2.6.3 Box Temperature Calibration Screen
In order to accurately determine when the internal leak source is running out of gas, the enclosure’s
temperature sensor must match the temperature of the leak source, as computed using the pressure/
temperature curve for the gas contained in the leak source and the measured pressure of the leak source.
Before making this adjustment, all enclosure lids must be in place and the instrument must be allowed to warm
up for at least 30 minutes.
Next, adjust the value displayed on the Box Temperature Calibration screen to match the calculated “LEAK”
temperature as displayed in the lower-right corner of the screen. In the example above, set the box temperature
for a reading of 28.41 by using the Left and Right buttons to move the blinking cursor across the screen to
highlight the digit to be modified, and then using the Up and Down buttons to modify that digit. Press ENT to
save the new box temperature value. Note that the “OFFSET” value is the difference between the box
temperature sensor reading, and the box temperature reading adjusted to match the leak source temperature.
5.2.7 Model Select
The Model Select function is used to set up the instrument’s operating characteristics as defined by its Part
Number (refer to Appendix “A”). Use the Up and Down buttons to select the appropriate Part Number (as
marked on the instrument’s rear panel). Press ENT to activate the selection.
S-Mpm/dP M-Mpm/dP
INT 0.0177/-1.33 0.0100/-2.28
FAC 0.0177/-1.33 0.0100/-2.28
ENTER TO SAVE INT AS FACTORY
ENTER BOX TEMP degC
2
8 .41
OFFSET=0.18 LEAK=28.41
MODEL SELECT
< 3015-4348 R134A
3015-4464
R600A
< 3015-4465 R600A