Endress+Hauser Cerabar M PMC41 - Performance Characteristics - General; Reference Operating Conditions; Reference Accuracy; Uncertainty of Measurement for Small Absolute Pressure Measuring Ranges

Cerabar M
Endress+Hauser 21
Performance characteristics – general
Reference operating
conditions
• As per IEC 60770
• Ambient temperature range T
A
= constant, in range: +21 to +33°C (+69.8 to +91.4°F)
• Humidity ϕ = constant, in range: 20 to 80% RH
• Ambient pressure p
U
= constant, in range: 860 to 1060 mbar
• Position of measuring cell = constant, in range: horizontal ±1°
• Input of LOW SENSOR CALIBRATION and HIGH SENSOR CALIBRATION for
lower-range value and upper-range value
• Membrane material PMC41 and PMC45: Al
2
O
3
(aluminum oxide ceramic)
• Membrane material PMP41, PMP45, PMP46 and PMP48: AISI 316L/1.4435
• Filling oil: synthetic oil
• Supply voltage: 24 V DC ± 3 V DC
• Load for HART: 250 Ω
• Turn down: 1:1 to 10:1
Reference accuracy Note!
In the case of overpressure measurement using absolute pressure sensors, the accuracy can be affected by
fluctuating ambient air pressure.
Uncertainty of measurement
for small absolute pressure
measuring ranges
The smallest expanded uncertainty of measurement that can be returned by our calibration standards is 0.4%
of the set span in the range 1 to 30 mbar.
Long-term stability • ±0.1% of URL/year
• ±0.25% of URL/3 years
Influence of the orientation A position-dependent zero point shift can be corrected within the (extended) measuring range. → See also the
following section "Raising and lowering the zero point", Page 25, "General installation instructions" section and
Page 65 ff, "Installation instructions, diaphragm seal systems" section.
Raising and lowering the zero
point
• 4 to 20 mA: ±10% within the extended measuring range
• 4 to 20 mA HART: as required within the extended measuring range
• PROFIBUS PA: as required within the extended measuring range
Examples for extended measuring limits and raising and lowering the zero point
P01-xxxxxxxx-05-xx-xx-xx-023
Case 1
Case 1:
• 4 to 20 mA HART or PROFIBUS PA
• And overpressure sensors with a lower-range limit
(LRL) > –1 bar
Example 1:
• Sensor measuring range: 0 to 10 bar
• Extended measuring range: –0.5 to 10.5 bar (the zero
point can be adjusted in this range)
P01-xxxxxxxx-05-xx-xx-xx-024
Case 2
Case 2:
• 4 to 20 mA HART or PROFIBUS PA
• Absolute pressure sensors and overpressure sensors with
a lower-range limit (LRL) = –1 bar
Example 2:
• Sensor measuring range: –1 to 10 bar
• Extended measuring rang: –1 to 10.5 bar (the zero point
can be adjusted in this range)
➀
➁
URL
5 % URL
• 5 % URL •
LRL
➀
➁
URL
5 % URL •
LRL