VEGA VEGAWELL 51 4 … 20 mA_HART User Manual
Page 31
Influence of the product or ambient temperature
A
pplies to digital HART interface as well as to analogue current output 4 … 20 mA.
S
pecifications refer to the set span. Turn down (TD) is the relation nominal measuring
range/set span.
Average temperature coefficient of the zero signal
I
n the compensated temperature range of 0 … +80 °C (+32 … +176 °F), reference
temperature 20 °C (68 °F).
A
verage temperature coefficient of the zero signal
-
T
urn down 1 : 1
<
0.15 %/10 K
-
T
urn down up to 5 : 1
<
0.2 %/10 K
-
T
urn down up to 10 : 1
<
0.25 %/10 K
O
utside the compensated temperature range:
A
verage temperature coefficient of the zero signal
-
T
urn down 1 : 1
typ. < 0.15 %/10 K
Thermal change, current output
A
pplies also to the analogue 4 … 20 mA current output and refers to the set span.
T
hermal change, current output
<
0.15 %
at -40 … +80 °C (-40 … +176 °F)
Long-term stability (similar to DIN 16086, DINV 19259-1 and IEC 60770-1)
A
pplies to digital HART interface as well as to analogue current output 4 … 20 mA.
S
pecifications refer to the set span. Turn down (TD) is the relation nominal measuring
range/set span.
L
ong-term drift of the zero signal
< (0.1 %
x TD)/year
Total deviation (similar to DIN 16086)
T
he total deviation F
t
,
also called practical deviation, is the sum of the basic accuracy F
p
and long-term stability:
F
t
= F
p
+ F
s
F
perf
= √((F
T
)
2
+ (F
K
l
)
2
)
W
ith
-
F
t
: F
total
,
total deviation
-
F
p
: F
perf
,
basic accuracy
-
F
s
: F
stab
,
long-term drift
-
F
T
: T
emperature coefficient
(
influence of medium or ambi-
ent temperature)
-
F
K
l
: D
eviation
S
upplement
VEGAWELL
51 • 4 … 20
mA/HART
31
32468
-
EN
-080604