Emerson Rosemount 248 - Thermocouples - ASTM E- 230; Rtds

58
Reference Manual
00809-0100-4825, Rev CB
Appendix A: Specifications and reference data
March 2014
Specifications and Reference Data
A.2.2 Thermocouples – ASTM E- 230
Applicable to sensors offered in Table A-4 on page A-58
Construction
Rosemount
1
/2-in. adapter style thermocouples are manufactured using ISA Type J or K wire with
special limits of error accuracy. The junction of these wires is fusion-welded to form a pure joint,
to maintain the integrity of the circuit and to ensure the highest accuracy.
Lead wires
Thermocouple, internal – 16 AWG solid wire (max), 18 AWG solid wire (min.). External lead wire
– 20 AWG wire, PTFE insulation. Color coded per ASTM E-230
Insulation resistance
100 megaohms minimum insulation resistance when measured at 100 Vdc at room
temperature
A.2.3 RTDs
Sensor type
100 ohm RTD at 0 °C,  = 0.00385 ohms/ohm/°C.
Accuracy
Meets IEC 751 Class B tolerances
Temperature range
–50 to 450 °C (–58 to 842 °F)
Self heating
0.15 °K/mW when measured per method defined in DIN EN 60751:1996 or 16 mW minimum
power dissipation required to cause a 1 °C (1.8 °F) temperature measurement error in water
flowing at 0.91 m/s (3 ft/s)
Table A-4. Characteristics of DIN Plate and
1
/2-in. NPT Adapter Style Thermocouples
Characteristics Type J Type K
Alloys (wire color) Iron/Constantan (white/red) Chromel/Alumel (yellow/red)
Temp Range 0 to 760 °C (32 to 1400 °F) 0 to 1150°C (32 to 2102 °F)
Tolerance ±1.1 °C or ±0.4% of measured
temp, whichever is greater
± 1.1 °C or ±0.4% of measured
temp, whichever is greater
Sheath Material 304 SST Inconel