Endress+Hauser iTEMP HART TMT142 Manuel De Mise En Service page 83

TMT142
Influence of cold junction
Ambient temperature limits
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Storage temperature
Operating height
Endress+Hauser
Typical sensor resistance change when process temperature changes by 1 K (1.8 °F):
Cu10: 0.04 Ω Pt200: 0.8 Ω
Cu100, Pt100: 0.4 Ω Pt500: 2 Ω
Typical change in thermoelectric voltage when process temperature changes by 1 K (1.8 °F):
B: 10 μV C: 20 μV
L: 55 μV N: 35 μV
Examples for calculating the accuracy:
• Example 1 (without the "Advanced Electronics" option):
Input temperature drift Δϑ = 10 K (18 °F), Pt100, span 0 to 100 °C (32 to 212 °F)
Maximum process value: 100 °C (212 °F)
Measured resistance value: 138.5 Ω (see IEC751)
Typ. influence in Ω: (0.002% of 138.5 Ω) * 10 = 0.0277 Ω
Conversion Ω to °C: 0.0277 Ω / 0.4 Ω/K = 0.07 K (0.013 °F)
• Example 2 (without the "Advanced Electronics" option):
Input temperature drift Δϑ = 10 K (18 °F), thermocouple type K with span 0 to 600 °C (32 to
1112 °F)
Maximum process value: 600 °C (1112 °F)
Measured thermoelectric voltage: 24905 μV (see IEC584)
Typ. influence in μV: (0.002% of 24905 μV) * 10 = 5 μV
Conversion Ω to °C: 5 μV / 40 μV/K = 0.12 K (0.216 °F)
• Example 3 (without the "Advanced Electronics" option):
Output temperature drift Δϑ = 10 K (18 °F), measuring range 0 to 100 °C (32 to 212 °F)
Span: 100 K (180 °F)
Typical influence: (0.002% of 100 K) * 10 = 0.02 K; (0.002% of 180 °F) * 10 = 0.036 °F
• Example 4 (with the "Advanced Electronics" option):
Max. possible measured error Δϑ = 10 K (18 °F), Pt100, measuring range 0 to 100 °C (32 to 212
°F)
Measured error Pt100: 0.1 K (0.18 °F)
Output measured error: 0.02 K (0.02% of 100 K); 0.04 °F (0.02% of 180 °F)
Input temperature drift: 0.03 K (0.05 °F)
Output temperature drift: 0.01 K * 1.5 = 0.015 K; (0.018 °F * 1.5 = 0.027 °F)
Max. possible error (total of errors): 0.165 K (0.297 °F)
Δϑ = deviation of ambient temperature from the reference operating condition
Total measuring point error = max. possible measured error + temperature sensor error
Pt100 DIN IEC 751 Cl. B (internal cold junction with thermocouples TC)
10.0.5 Environment
• Without display: -40 to +85 °C (-40 °F to +185 °F)
• With display: -40 to +80 °C (-40 °F to +176 °F)
For use in hazardous areas, see Ex certificate
Note!
The display can react slowly for temperatures < -20 °C (< -4 °F). Readability of the display cannot
be guaranteed at temperatures < -30 °C (-22 °F).
• Without display: -40 to +100 °C (-40 °F to +212 °F)
• With display: -40 to +85 °C (-40 °F to +185 °F)
Up to 2000 m above MSL
Ni120: 0.7 Ω Cu50: 0.2 Ω
Pt1000: 4 Ω Ni100: 0.6 Ω
D: 20 μV E: 75 μV
R: 12 μV S: 12 μV
Technical data
Pt50: 0.2 Ω
Ni1000: 6 Ω
J: 55 μV K: 40 μV
T: 50 μV U: 60 μV
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