Valmet TS, Инструкция по установке и эксплуатации, Страница: 28 / 63

Temperature compensation correction
The Valmet TS compensates for the effect of temperat-
ure by using a temperature measurement. If temperat-
ure sensitivity is still observed in the measurement
result, it can be eliminated by temperature compensa-
tion correction. First determine the actual temperature
dependence by means of laboratory monitoring. To
ensure reliable results, both the sampling and laborat-
ory analyses must be accurate and reliable, and also
the temperature range must be wide enough.
The results of laboratory monitoring are shown in a
TS-Lab vs. Temp graph. If the TS-Lab points are on a
horizontal graph, the Valmet TS measurement results
show no dependence on temperature. If the graph is
horizontal but are not at zero level, perform a level
correction to the calibration as instructed in section 7.3.
If the graph is not horizontal, the Valmet TS meas-
urement results show some dependence on temperat-
ure (Fig. 1). To eliminate this effect, enter a correction
curve for the temperature compensation. Select "Spe-
cial functions" -› "Temperature comp", and the following
display will appear:
T e m p T S - L a b
1 . 0 . 0 0 0 . 0 0
2 . 0 . 0 0 0 . 0 0
3 . 0 . 0 0 0 . 0 0
4 . 0 . 0 0 0 . 0 0
5 . 0 . 0 0 0 . 0 0
6 . 0 . 0 0 0 . 0 0
Press "Edit/Save". Then enter the correction curve
as point pairs, Temp/TS-Lab. The Valmet TS will use
this data to correct the compensation. Up to six point
pairs can be entered. In the case shown in Fig. 1 two
point pairs are enough, and based on the results these
can be selected for example as follows:
T e m p T S - L a b
1 . 4 2 . 0 0 . 0 0
2 . 4 8 . 1 0 . 1 0
3 . 0 0 . 0 0 . 0 0
4 . 0 0 . 0 0 . 0 0
5 . 0 0 . 0 0 . 0 0
6 . 0 0 . 0 0 . 0 0
Compensation is also successful outside the defined
interval such that the compensation curve is continued
beyond the outermost points using the same slope.
TS-Lab vs Temp
-0,2
-0,15
-0,1
-0,05
0
0,05
0,1
0,15
0,2
41 42 43 44 45 46 47 48 49 50
Temp (°C)
T
S
-L
a
b
(%
)
Fig. 1. Determining temperature dependence.
Installation & Owner's manual, OUL00489 V2.3 EN 28 Valmet Total Solids Transmitter