Example of RTD analog input deadband supervision
Temperature sensor Pt100 is used in the temperature range of 15...180 °C.
Value unit “Degrees Celsius” is used and the set values Value minimum and
Value maximum are set to 15 and 180, respectively.
Value deadband = 7500 (7.5% of the total measuring range 165)
AI_VAL# = AI_DB# = 85
If AI_VAL# changes to 90, the reporting delay is:
t s
( )
(
)
.
=
° −
°
⋅
° −
°
≈
180
15
7500
100000
90
85
2 5
C
C
%s
s
C
C
s
(Equation 5)
Table 55: Settings for RTD analog input deadband supervision
Funtion
Setting
Maximum/minimum
(=range)
RTD analog input
Value deadband
Value maximum / Value
minimum (=20000)
Since the function can be utilized in various measurement
modes, the default values are set to the extremes; thus,
it is very important to set correct limit values to suit
the application before the deadband supervision works
properly.
3.13.2.9
RTD temperature vs. resistance
Table 56: Temperature vs. resistance
Temp
°C
Platinum TCR 0.00385
Nickel TCR 0.00618
Copper
TCR
0.00427
Pt 100
Pt 250
Ni 100
Ni 120
Ni 250
Cu 10
-40
84.27
210.675
79.1
94.92
197.75
7.49
-30
88.22
220.55
84.1
100.92
210.25
-
-20
92.16
230.4
89.3
107.16
223.25
8.263
-10
96.09
240.225
94.6
113.52
236.5
-
0
100
250
100
120
250
9.035
10
103.9
259.75
105.6
126.72
264
-
20
107.79
269.475
111.2
133.44
278
9.807
30
111.67
279.175
117.1
140.52
292.75
-
40
115.54
288.85
123
147.6
307.5
10.58
50
119.4
298.5
129.1
154.92
322.75
-
Table continues on the next page
Basic functions
1MRS757644 H
124
620 series
Technical Manual
