Martel Electronics 235 - Manual (Page 43)

appear.
This menu allows the selection of engineering units for pressure
display. The choices are displayed 4 at a time. Scrolling past the first or
last displayed selection provides additional choices.
The engineering units available are: PSI, inH₂O, inHg, Kpa, cmH₂O,
mmHg, mbar, Bar. The selection between absolute and gauge is made
automatically based on the type of module attached.
When any of the water column scales are selected from the main
engineering units menu, a second menu will be displayed that allows
the operator to select the conversion temperature desired. 20°C is the
Instrument Society of America (ISA) standard, 60°F is used by the
American Gas Association (AGA) and 4°C is used in scientific research.
Software versions prior to 03.35 use the 4°C conversion temperature.
The factors used by the Pressure Module to convert from PSI to other
engineering units are listed below.
2.036 “Hg @0°C
51.715 mmHg @0°C
6.8948 KPascals
68.948 milliBars
0.068948 Bars
27.681 “H2O @4°C
27.707 “H2O @60°F
27.730 “H2O @20°C
70.310 cmH2O @4°C
70.376 cmH2O @60°F
70.433 cmH2O @20°C
When the OPT key is pressed a subsequent time(s), the calibrator
checks the ID and serial number of the attached module. If these
match the previous values, the module is activated immediately,
bypassing the title and serial number displays.
Input Functions
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Engineering Unit
PSI “H2O “Hg Kpa