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Reference Manual
00809-0400-4728, Rev AA
June 2011
A-3
Rosemount 644
Performance EMC (ElectroMagnetic Compatibility)
NAMUR NE 21 Standard
The 644H HART meets the requirements for NAMUR NE 21 Rating.
CE Mark
The 644 is compliant with Directive 2004/108/EC. Meets the criteria under
IEC 61326:2006.
Power Supply Effect
Less than ±0.005% of span per volt
Stability
RTDs and thermocouples have a stability of ±0.15% of output reading or 0.15
°C (whichever is greater) for 24 months.
Self Calibration
The analog-to-digital measurement circuitry automatically self-calibrates for
each temperature update by comparing the dynamic measurement to
extremely stable and accurate internal reference elements
Vibration Effect
The 644 is tested to the following specifications with no effect on performance
per IEC 60770-1, 1999:
Sensor Connections
Frequency Vibration
10 to 60 Hz 0.21 mm displacement
60 to 2000 Hz 3 g peak acceleration
644244EH Sensor Connections Diagram
* Rosemount Inc. provides 4-wire sensors for all single element RTDs. You can use these RTDs in 3-wire
configurations by leaving the unneeded leads disconnected and insulated with electrical tape.
2-wire
RTD and ⍀
3-wire RTD
and ⍀
4-wire RTD
and ⍀
T/C
and mV
*
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