DH Instruments PPC4, Operation And Maintenance Manual

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PPC4™ OPERATION AND MAINTENANCE MANUAL
© 2009 DH Instruments, a Fluke Company Page 212
9.2 Unit Conversion
9.2.1 Pressure
PPC4 performs all internal calculations in SI units. Numerical values input or output in other units are
converted to SI immediately after entry and back to other units just before output as needed.
Table 30 provides the conversion coefficients used by PPC4 to convert numerical values
expressed in SI units to corresponding values expressed in other units.
Table 35. Pressure Unit of Measure Conversion Coefficients
TO CONVERT FROM Pa To MULTIPLY BY
Pa Pascal 1.0
mbar millibar 1.0 E-02
hPa
hecto Pascal
1.0 E-02
kPa kilo Pascal 1.0 E-03
bar bar 1.0 E-05
mmH2O @ 4°C millimeter of water at 4°C 1.019720 E-01
mmH2O @ 20°C millimeter of water at 20°C 1.019716 E-01
mmH2O @ 60°F millimeter of water at 60°F 1.018879 E-01
mH2O @ 4°C meter of water at 4°C 1.019720 E-04
mH2O @ 20°C
meter of water at 20°C
1.019716 E-04
mH2O @ 60°F meter of water at 60°F 1.018879 E-04
mmHg @ 0°C millimeter of mercury 7.50063 E-03
psi pound per square inch 1.450377 E-04
psf pound per square foot 2.0885429E-02
inH2O @ 4°C inch of water at 4°C 4.014649 E-03
inH2O @ 20°C inch of water at 20°C 4.021732 E-03
inH2O @ 60°F
inch of water at 60°F
4.018429 E-03
inHg @ 0°C inch of mercury 2.953 E-04
kcm
2
kilogram force per centimeter square 1.019716 E-05
mTorr milliTorr (micron of mercury 7.50063
Torr Torr (millimeter of mercury) 7.50063 E-3
user user User defined coefficient
ft feet of altitude see Altitude Note below
m meter of altitude see Altitude Note below
Altitude Note: Quantities expressed in units of altitude follow MIL-STD-859A “Static
Pressure, p, in Inches of Mercury for Values of Pressure Altitude, H, in Geopotential
Feet.” MIL-STD-859A provides tables of pressure in inches of mercury as a function of
altitude in feet. PPC4 uses a set of equations to model the pressure/altitude
relationship. The worst case deviation between the MIL-STD-859A table and the
calculated pressure is 0.0001 inches of mercury (0.3 Pa). The pressure quantity
expressed in inches of mercury is converted to Pascal following Table 30 above. For
altitude expressed in meters, meters are converted to feet using 1 m = 3.28084 ft.