Fluke 7381 - Calibration Example

Calibration Bath
Calibration Procedure
49
Calibration Example
The Bath is to be used between 25 °C and 75 °C and it is desired to calibrate the Bath as
accurately as possible for operation within this range. The current values for R
0
and ALPHA are
100.000 and 0.0038500, respectively. The calibration points are chosen to be 30.00 and
80.00 °C. The measured Bath temperatures are 29.843 °C and 79.914 °C respectively. Refer to
Figure 7 to apply equations to the example data and to compute the new probe constants.
Figure 7. Calibration Example
R
0
= 100.000
ALPHA = 0.0038500
t
L
= 30.00 °C
measured t = 29.843 °C
t
H
= 80.00 °C
measured t = 79.914 °C
Compute errors,
err
L
= 29.843 - 30.00 °C = -0.157 °C
err
H
= 79.914 - 80.00 °C = -0.086 °C
Compute R0′,
R
0
0 086 30 0 0157 80 0
80 0 30 0
0 00385 1′=
uu


(. ) . (. ) .
..
. 100 000 100 077..
Compute ALPHA′,
ALPHA′=
u u(. .)(.)(. .)(1 0 00385 80 0 0157 1 0 00385 30 0
0 086
80 0 30 0
1 0 00385 0 0038416
.)
..
..

