60
10 Supplement
WIKA Operating Instructions - Process pressure transmitter CPT-2x
(
F
TBasis
Fig. 39: 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,
depending on the measuring cell version (factor FMZ) and the Turn Down (factor FTD). The ad-
ditional factors are listed in the following tables.
Additional factor through measuring cell version
Measuring cell version
Measuring cell standard, depending on the accuracy class
0.05 %, 0.1 %
0.2 % (with measuring
range 0.1 bar
abs
)
0.2 %
0.05 %, 0.1 % with meas-
uring range 25 mbar
Factor FMZ
1
2
3
Measuring cell version
Measuring cell climate-compensated, depending on measuring range
-1 … 0 bar, -1 … 1,5 bar,
10 bar, 25 bar, 60 bar,
100 bar
-0.5 … 0.5 bar, 1 bar,
2,5 bar
0.4 bar, -0.2 … 0.2 bar
Factor FMZ
1
2
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 5 : 1
TD 10 : 1
TD 20 : 1
Factor FTD
1
1.75
3
5.5
10.5
Long-term stability (according to DIN 16086)
Applies to the respective
digital signal output (e.g. HART, Profibus PA) as well as to analogue
cur-
rent output 4 … 20 mA under reference conditions. Specifications refer to the set span. Turn down
(TD) is the ratio nominal measuring range/set span.
