EN
68
WIKA operating instructions, model CTR3000
14191761.01 05/2019 EN/DE
7. Technical information about temperature
themselves be the source of contamination at elevated temperatures. The PRTs supplied by WIKA have been optimised for the
temperature ranges for which they are specified and, when calibrated, are temperature cycled to enhance stability in use.
PRTs which are used outside their design and/or calibration temperature range, especially at higher temperatures, risk
irreversible alteration to their calibration either by induced thermal stresses or by contamination.
7.3.2.1 Linearisation functions for resistance thermometers
The CTR3000 provides one standard and 2 user definable algorithms for converting resistance to temperature. The choice will
depend on the type of PRT and its calibration.
Standard: EN 60751 (2009):
Used for un-calibrated industrial PRTs with 0.003851 “alpha” value, to provide a conversion of resistance to temperature in
accordance with the EN 60751 (ITS-90) standard.
Selecting EN 60751 from the standard menu selects the standard coefficients from BS EN 60751 based on ITS-90.
The coefficients for EN 60751 are as follows:
R
0
= 100 Ω
A = 3.9083 x 10
–3
°C
–1
B = -5.775 x 10
–7
°C
–2
C = -4.183 x 10
–12
°C
–4
