WIKA TR12-M - Handbuch (Seite 9)

GB
3. Specifications
11419904.02 09/2013 GB/D
WIKA operating instructions models TR12, TC12 (Ex d) 9
3. Specifications
3.1 Resistance thermometer
Sensor connection method
■ 2-wire
■ 3-wire
■ 4-wire
Sensor tolerance value per DIN EN 60751
■ Class B
■ Class A
■ Class AA
The combinations of a 2-wire connection with class A or class AA are not permissible, since
the lead resistance of the measuring insert negates the higher sensor accuracy.
Basic values and tolerance values
Basic values and tolerance values for the platinum measurement resistances are laid down
in DIN EN 60751.
The nominal value of Pt100 sensors is 100 Ω at 0 °C. The temperature coefficient α can be
stated simply to be between 0 °C and 100 °C with:
α = 3.85 ∙ 10 -3 °C -1
The relationship between temperature and electrical resistance is described by
polynomials, which are also defined in DIN EN 60751. Moreover, this standard specifies the
basic values in °C steps in tabular form.
Class Temperature range Tolerance value in °C
Wire-wound (W) Thin-film (F)
B -196 … +600 °C -50 … +500 °C ±(0.30 + 0.0050 | t |) 1)
A -100 … +450 °C -30 … +300 °C ±(0.15 + 0.0020 | t |) 1)
AA -50 … +250 °C 0 … +150 °C ±(0.10 + 0.0017 | t |) 1)
1) | t | is the value of the temperature in °C without consideration of the sign.
Bold: Standard version
For further technical information, see WIKA data sheet and the technical information sheet
IN 00.17 “Usage limitations and accuracies of platinum resistance thermometers per
EN 60751: 2008”.