52
9 Supplement
WIKA Operating Instructions - Process pressure transmitter IPT-2x
Accuracy class
Non-linearity, hysteresis and repeata-
bility with TD 1 : 1 up to 5 : 1
Non-linearity, hysteresis and repeata-
bility with 5 : 1
0.075 %
< 0.075 %
< 0.015 % x TD
0.1 %
< 0.1 %
< 0.02 % x TD
0.2 %
< 0.2 %
< 0.04 % x TD
Influence of the product temperature
Thermal change zero signal and output span
Turn down (TD) is the relation nominal measuring range/adjusted span.
The thermal change of the zero signal and output span corresponds to the value F
T
in chapter
"
Calculation of the total deviation (according to DIN 16086)
".
Piezoresistive/strain gauge measuring cell
(TD 1:1)
T / °C
50 °C
10 °C 20 °C
40 °C
70 °C
-40 °C
100 °C
150 °C
0,15
-0,15
-0,3
-0,45
-0,6
-0,75
-0,9
0,3
0,45
0,6
0,75
0,9
F/
%
TBasis
Fig. 27: Basic temperature error F
TBasis
at TD 1 : 1
The basic temperature error in % from the above graphic can increase due to the additional factors
such as accuracy class (factor FMZ) and Turn Down (factor FTD). The additional factors are listed
in the following tables.
Additional factor through accuracy class
Accuracy class
0.075 %, 0.1 %
0.2 %
Factor FMZ
1
3
Additional factor through Turn Down
The additional factor FTD through Turn down is calculated according to the following formula:
F
TD
= 0.5 x TD + 0.5
In the table, example values for typical Turn downs are listed.
Turn down
TD 1 : 1
TD 2.5 : 1
TD : 1
TD 10 : 1
TD 20 : 1
Factor FTD
1
1.75
3
5.5
10.5
