Endress+Hauser Cerabar PMC11 - Performance Characteristics of Ceramic Process Isolating Diaphragm; Reference Operating Conditions; Measuring Uncertainty for Small Absolute Pressure Measuring Ranges; Influence of the Installation Position

Cerabar PMC11, PMC21, PMP11, PMP21
20 Endress+Hauser
Performance characteristics of ceramic process isolating
diaphragm
Reference operating
conditions
• As per IEC 60770
• Ambient temperature T
A
= constant, in the range of:+21 to +33 °C (+70 to +91 °F)
• Humidity φ = constant, in the range of 5 to 80 % rH
• Ambient pressure p
A
= constant, in the range of:860 to 1 060 mbar (12.47 to 15.37 psi)
• Position of measuring cell = constant, in range: horizontal ±1° (see also "Influence of the
installation position" section →  23)
• Zero based span
• Material of process isolating diaphragm: Al
2
O
3
(aluminum-oxide ceramic, Ceraphire
®
)
• Supply voltage: 24 V DC ±3 V DC
• Load: 320 Ω (at 4 to 20 mA output)
Measuring uncertainty for
small absolute pressure
measuring ranges
The smallest extended uncertainty of measurement that can delivered by our standards is:
• in range 1 to 30 mbar (0.0145 to 0.435 psi): 0.4 % of reading
• in range < 1 mbar (0.0145 psi): 1 % of reading.
Influence of the installation
position
→  23
Resolution
Current output: min. 1.6 μA
Reference accuracy
The reference accuracy contains the non-linearity [DIN EN 61298-2 3.11] including the pressure
hysteresis [DIN EN 61298-23.13] and non-repeatability [DIN EN 61298-2 3.11] in accordance with
the limit point method as per [DIN EN 60770].
Device % of the calibrated span to the maximum turn down
Reference accuracy Non-linearity
1)
Non-repeatability
PMC11
2)
±0.5 ±0.1 ±0.1
PMC21 ±0.3 ±0.1 ±0.1
1) The non-linearity for the 40 bar (600 psi) sensor can be up to ± 0.15% of the calibrated span up to the
maximum turn down.
2) For devices with 0 to 10 V output, a non-linearity of up to max. 0.3 V can occur for signal values below
0.03 V.
Overview of the turn down ranges →  14
Measuring ranges Turn down Device % of URL
100 mbar (1.5 psi)to
40 bar (600 psi)
1:1 to TD 5:1 PMC11 ±0.5
PMC21 ±0.3
1)
1) For the 100 mbar (1.5 psi) and 250 mbar (4 psi) measuring ranges, the following applies: In the event of
heat effects on the initial reference conditions, an additional deviation of max. 0.3 mbar (4.5 psi) from the
zero point or the output span is possible.
Thermal change of the zero
output and the output span
Measuring cell –20 to +85 °C (–4 to +185 °F) –40 to –20 °C (–40 to –4 °F)
+85 to +100 °C (+185 to +212 °F)
% of URL for TD 1:1
<1 bar (15 psi) <1 <1.2
≥ 1 bar (15 psi) <0.8 <1