Emerson Rosemount 248 - Sensor Specifications; Thermocouples - IEC 584

57
Reference Manual
00809-0100-4825, Rev CB
Appendix A: Specifications and reference data
March 2014
Specifications and Reference Data
Transmitter temperature effects example
Transmitters can be installed in locations where the ambient temperature is between –40 and
85 °C (–40 and 185 °F). In order to maintain excellent accuracy performance, each transmitter is
individually characterized over this ambient temperature range at the factory.
When using a Pt 100 ( = 0.00385) sensor input with a 0-100 °C span at 30 °C ambient tempera-
ture-Temperature Effects: 0.006 °C x (30 - 20) = 0.06 °C
Total transmitter error
Worst Case Transmitter Error: Accuracy + Temperature Effects = 0.2 °C + 0.06 °C = 0.26 °C
Total Probable Transmitter Error:
A.2 Sensor specifications
A.2.1 Thermocouples – IEC 584
Applicable to sensors offered in Table A-3 on page A-57
Construction
Rosemount DIN plate and
1
/2-in. adapter style thermocouples are manufactured from selected
materials to meet IEC 584 Tolerance Class 1. The junction of these wires is laser-welded to form a
pure joint, maintaining circuit integrity and ensuring highest accuracy.
Lead wires
Internal – 18 SWG (16 AWG) solid wire (max), 19 SWG (18 AWG) solid wire (min.). External
extension leads, type J and K – 0.8 mm minimum stranded wire, PTFE insulation. Color coded
per IEC 584
Insulation resistance
1000 megaohms minimum insulation resistance when measured at 500 Vdc at room
temperature.
Table A-3. Characteristics of DIN Plate and
1
/2-in. NPT Adapter Style Thermocouples
Characteristics Type J Type K
Alloys (wire color) Fe (+ black), CuNi (- white) NiCr (+ green), NiAl (- white)
Sheath Material 1.4541 (AISI 321) Inconel 600
Temp Range (°C) – 40 to 750 – 40 to 1000
Tolerance, DIN EN 60584-2 ±1.5 °C or ±0.4% of measured temp, whichever is greater
0.2
2
0.06
2
+ 0.21=