Eurotherm 6100, Руководство пользователя

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100/180MM DISTRIBUTED GRAPHIC RECORDER: USER GUIDE
HA029324
Issue 11 Oct 14 Page 111
4.3.11 FUNCTION (Cont.)
SATURATED STEAM MASS FLOW (Cont.)
PRESSURE UNITS CONVERSION
There is a wide range of pressure measuring units in use throughout the world. The following table
gives a multiplication factor for converting some common units to MPa (MegaPascals), to four signifi cant
fi gures. Further conversion factors can be found at the websites given on the previous page. (Where the
conversion is to Pascals, not to MegaPascals, the factors given have to be divided by 1,000,000.)
Pressure units
Multiplier for
MPa
Atmospheres 0.1013
Bar 0.1
kg/cm2 0.09 807
kNewton/m2 0.001
kPa 0.001
mBar 0.0001
Lb/ft2 0.00 004 788
Lb/in2 (PSI) 0.006 895
Mercury (inches of) 0.003 386
Mercury (mm of)
0.0 001 333
Newtons/cm2 0.01
Newtons/m2 0.000 001
Pascals 0.000 001
Tonnes/m2 0.009 807
Tons(UK)/ft2 0.1 073
Tons(US)/ft2 0.09 576
Water (feet of) 0.002 989
Water (inches of) 0.0 002 491
Water (mm of) 0.000 009 807
Pressure units
Multiplier for
MPa
Function
Multiply
by
Constant Value
Units
Maths Number
Value
Units
Apply Discard
Descriptor
Scale low
Scale high
MPa
MPa
Multiply
Channel 3
0.006895
MPa
2) Steam Pressure
0.0348
Constant
Steam Pressure
0
1
Table 4.3.11b Pressure unit conversion
The table above shows multiplying factors to convert common pressure units to MPa. This conversion is
carried out as follows:
Example: A pressure transducer, connected to input channel 3 gives an output in the range 10 to 100 PSI.
The input to a steam equation in maths channel 1 requires the pressure units to be MPa. To convert, set
up a further maths channel (e.g. No. 2) as shown below, then use maths channel 2 as the source channel
for the pressure input to the steam equation.
The suggested scale low/high values are based on the resulting pressure range in MPa -i.e 0.06895 to
0.6895.
Figure 4.3.11i PSI to MPa conversion example