VEGA VEGABAR 67 Profibus PA - climate compensated - Manual (Page 48)

48
8 Maintenance and fault rectification
VEGABAR 67 • Profibus PA - climate compensated
39445-EN-130321
Error code Cause Rectification
E113 Communication con-
flict
– Exchange the instrument or send it
in for repair
8.3 Calculation of total deviation (according to
DIN 16086)
The total deviation F
total
according to DIN 16086 is the sum of basic
accuracy F
perf
and longterm stability F
stab
. F
total
is also called maximum
practical deviation or utility error.
F
total
= F
perf
+ F
stab
F
perf
= √((F
T
) 2 + (F
Kl
) 2 )
With:
•
F
total
: Total deviation
•
F
perf
: Basic accuracy
•
F
stab
: Long-term drift
•
F
T
: Temperature coefficient (influence of medium or ambient
temperature)
•
F
Kl
: Deviation
Level measurement 1.5 mWs
Ambient temperature 40 °C, product temperature 10 °C
VEGABAR 67 with measuring range 0.2 bar
Deviation < 0.1 %
Calculation of the set Turn Down:
TD = 200 mbar/147 mbar, TD = 1.4
Basic accuracy digital output signal in percent:
F
perf
= √((F
T
) 2 + (F
Kl
) 2 )
F
T
= (0.15 + 0.4 x TD) %
F
Kl
= 0.1 %
F
perf
= √((0.15 % + 0.4 % x 1.4) 2 + (0.1 %) 2 )
F
perf
= 0.72 %
Total deviation digital output signal in percent:
F
total
= F
perf
+ F
stab
F
stab
= (1 % x 1.4)/year
F
stab
= 1.4 %
F
total
= 0.72 % + 1.4 % = 2.12 %
Total deviation digital output signal absolute:
F
total
= 2.12 % x 147 mbar/100 % = 3.11 mbar = 31.77 mm
8.4 Exchanging the electronics module
In case of a defect, the electronics module can be exchanged by the
user against an identical type. If no electronics module is available on
side, the module can be ordered from the agency serving you.
Total deviation
Example