Riele Photometer 5010 - Linear Interpolation

9.1 CALIBRATION PROCEDURE OF
PHOTOMETER 5010
SUBJECT: CUVETTE TEMPERATURE
RIELE BERLIN Photometer 5010 / V4 9.1.4 25.08.2003
9. Linear interpolation
This procedure describes the performing of a linear interpolation in case of a given resistance R.
The assigned temperature is called T.
If the resistance R is found in the table, get the appropriate temperature value and finish this chapter.
If the actual temperature of the thermistor is in the range of the required temperature ± 1.5 °C, two values
of resistance can be read from table with the relation:
R
0
> R > R
1
The resistances R
0
and R
1
form an interval. They are a set of data points next to the resistance R.
The assigned temperature values of the resistances
R
0
and R
1
are called T
0
and T
1
.
The assigned temperature T can be calculated by the formula:
T = T
0
+ (T
1
– T
0
) × (R - R
0
) / (R
1
– R
0
)
Example:
In case of a given resistance R with the value 9978 Ohm you can find the interpolated temperature T by:
T = 25 °C + 0.1 °C × (9978 - 10000) / (9956 – 10000)
T = 25.05 °C