ABB 266 MODBUS - Table 5: RTD Input Specifications; Table 6: RTD Element Errors

2 System description
10 | 266 MODBUS® multivariable transmitter User manual 2105216 Rev. AB
Resistance thermal detector (RTD) input
The transmitter includes inputs to measure a 4-wire RTD probe. When properly installed, the RTD probe measures fluid
temperature in a process line. The input supports a platinum 100 ohm @ 0° C, RTD with a temperature coefficient of resistance
(TCR) Curve B of .00385055 ohms/ohm/degree C. The RTD input specifications are documented in Table 5. The calculation
table for RTD element errors is documented in Table 6.
Table 5: RTD input specifications
6
Item
Description
Accuracy
7
±0.27 ° F Typical
±0.65 °F Maximum
Over operating range of: -54 °F to +765 °F
Measurement range
-80 °F to +1500 °F
Table 6: RTD element errors
8
Tolerance
class
Temperature range of validity °C
Wire wound elements Film elements
Tolerance Values
9
°C
AA
-50 to +250
0 to +150
±(0.1 + 0.0017|t|)
A
-100 to +450
-30 to +300
±(0.15 + 0.002|t|)
B
-196 to +600
-50 to +500
±(0.3 + 0.005|t|)
C
-196 to +600
-50 to +600
±(0.6 + 0.01|t|)
6
Does not include RTD probe errors
7
Measurement accuracy before user calibration
8
Per IEC 60751, Edition 2.0 2008 – 07
9
|t| = modulus of temperature in °C without regard to sign