mensor CPC8000, Руководство по эксплуатации

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High-End Pressure Controller
CPC8000
Operating Instructions - CPC8000 23
4.7 IntelliScale
IntelliScale is a calibration technique that provides another degree of certainty to a pressure
measurement specifcation. Or said another way, IntelliScale is designed to further reduce the
uncertainty specifcation. It does this by considering the full pressure range as two separate ranges; a
specifcally defned lower range, and the remaining upper range. It then defnes the uncertainty of the
lower portion as a percent of the full scale of that lower range, and the uncertainty of the upper portion as
a percent of reading at any pressure point within that upper range.
In practice, the standard Mensor IntelliScale specifcation is 0.01% IS-50. This means that the full scale
lower half (50% of the total range) has an uncertainty of 0.01% of that portion of the range, while the
upper half of the total range has an uncertainty of 0.01% of the pressure reading. Thus, any pressure
within the lower half of the pressure range has a fxed number for the uncertainty (.01% of that half scale),
while the uncertainty anywhere in the upper half of the full range is a sliding scale number; that is, a
percent (0.01%) of any reading.
For example, a device with a pressure range from 0 to 100 psi with an uncertainty specifcation of Intel-
liScale 0.01% IS-50 will have an uncertainty of 0.005 psi (0.01% x 50 psi FS) on any pressure from 0 psi
to 50 psi, and an uncertainty of 0.01% of reading (0.01% x R) for any pressure above 50 psi (see fgure
4.7.1a).
4.7.1 Optional IntelliScale
An option available for some ranges is IntelliScale 0.008% IS-33, where the lower portion of the full scale
range is 33% of the total range, and the upper portion of the full scale range is 67% of the full range. The
result is an uncertainty of 0.00264% (0.008% x 33% FS) of the total full scale pressure for the one third
low end range, and an uncertainty of 0.008% of reading (0.008% x R) for any pressure in the upper two
thirds of the transducer range. See fgure 4.7.1b.
50 20 40 60 80 100
To
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0.
01
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%FS Pressure
Total Uncertainty
0.01% of 50%
of FS pressure
0 20 40 60 80 100
To
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0.
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8%
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%FS Pressure
33
Total Uncertainty
0.008% of 33%
of FS pressure
Figure 4.7.1a - IntelliScale IS-50 Figure 4.7.1b - IntelliScale IS-33