Calculation Of Total Deviation (According To Din 16086) - Vega VEGABAR 52 Operating Instructions Manual

Total deviation
Example
VEGABAR 52 • 4 ... 20 mA/HART
8.3 Calculation of total deviation (according to
DIN 16086)
The total deviation F
total
accuracy F and longterm stability F
perf
maximum practical deviation or utility error.
= F + F
F
total perf stab
2
= √((F + (F
F ) )
perf
T Kl
With the analogue signal output there is also the error of the current
output F
.
a
2
= √((F + (F
F ) )
perf
T Kl
With:
: Total deviation
F
l
total
: Basic accuracy
F
l
perf
: Long-term drift
F
l
stab
: Temperature coefficient (influence of medium or ambient
F
l
T
temperature)
F : Deviation
l
Kl
: Error current output
F
l
a
Pressure measurement in the pipeline 8 bar (800 KPa)
Product temperature 50 °C, hence within the compensated range
VEGABAR 52 with measuring range 10 bar
Calculation of the set Turn Down: TD = 10 bar/8 bar, TD = 1.25
Basic accuracy digital output signal in percent:
2
= √((F + (F
F ) )
perf
T Kl
= (0.05 % + 0.1 % x TD)
F
T
= 0.075 %
F
Kl
= √((0.05 % + 0.1 % x 1.25)
F
perf
= 0.19 %
F
perf
Total deviation digital output signal in percent:
= F + F
F
total perf stab
= (0.1 % x TD)/year
F
stab
= (0.1 % x 1.25)/year
F
stab
= 0.125 %
F
stab
= 0.19 % + 0.125 % = 0.315 %
F
total
Total deviation digital output signal absolute:
= 0.315 % x 8 bar/100 % = 25.2 mbar
F
total
8 Maintenance and fault rectification
according to DIN 16086 is the sum of basic
. F
stab
2
)
2 2
+ (F
) )
a
2
)
2
+ (0.075 %)
is also called
total
2
)
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