WIKA DPT-20, Руководство по эксплуатации

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79
10 Supplement
WIKA Operating Instructions - Differential pressure transmitter DPT-20
Measured variable
Time range
1 year 5 years 10 years
Static pressure
24)
< ±0.065 % < ±0.1 % < ±0.15 %
4. Calculation of the total deviation - digital output signal
- 1. step: Basic accuracy F
perf
F
perf
= √((F
T
)
2
+ (F
Kl
)
2
)
F
T
= 0.25 %
F
Kl
= 0.065 %
F
perf
= √(0.25 %)
2
+ (0.065 %)
2
)
F
perf
= 0.26 %
- 2. step: Total deviation F
total
F
total
= F
perf
+ F
stab
F
perf
= 0.26 % (result of step 1)
F
stab
= 0.065 % x TD
F
stab
= 0.065 % x 2
F
stab
= 0.13 %
F
total
= 0.26 % + 0.13 % = 0.39 %
The total percentage deviation of the measurement is thus 0. 39%. The absolute total deviation is
0. 39% of 250 mbar = 1 mbar
The example shows that in practice the error of use can be significantly higher than the actual
measurement error. The causes are temperature influence and turn down.
10.5 Dimensions, versions process component
Plastic housing
~ 69 mm
(2.72")
ø 77 mm
(3.03")
112 mm (4.41"
)
M20x1,5/
½ NPT
~ 84 mm (3.31")
M16x1,5
112 mm (4.41"
)
M20x1,5/
½ NPT
1 2
ø 84 mm
(3.31")
1 Plastic single chamber
2 Plastic double chamber
24)
Relating to the measuring range end value.