Vega VEGADIF 85 - Dimensions, Versions Process Component

90
11 Supplement
VEGADIF 85 • Modbus and Levelmaster protocol
53571-EN-230814
3. Determination of deviation and long-term stability
Deviation
Measuring range TD 1 : 1 up to 5 : 1 TD > 5 : 1 TD > 10 : 1
10mbar(1kPa)/0.145psi < ±0.1 %
< ±0.02 % x TD
30mbar(3kPa)/0.44psi
100mbar(10kPa)/1.5psi
< ±0.065 %
<±(0.035%+0.01%)xTD
500mbar(50kPa)/7.3psi
3bar(300kPa)/43.51psi <±(0.015%+0.005%)xTD
16bar(1600kPa)/232.1psi <±(0.035%+0.01%)xTD
Long-term stability
Measured variable
Time range
1 year 5 years 10 years
Dierentialpressure
22)
< 0.065 % x TD < 0.1 % x TD < 0.15 % x TD
Static pressure
23)
< ±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signicantlyhigherthantheactual
measurementerror.Thecausesaretemperatureinuenceandturndown.
11.9 Dimensions, versions process component
The following dimensional drawings represent only an extract of the possible versions. Detailed
dimensional drawings can be downloaded at www.vega.com under " Downloads" and " Drawings".
22)
Relating to the adjusted span.
23)
Relating to the measuring range end value.