Dry-well Calibrator
Calibration and Adjustment Procedure
27
Compute R0 and ALPHA
delta
is the new value of DELTA computed above.
Program the new values for DELTA (delta), R0 (rzero), and ALPHA (alpha) into the dry-well with the
following steps.
1. Press
SET
and
EXIT
at the same time. Press
SET
until 5. PAR displays. and then press
u
until
CAL
displays.
2. Press
SET
five times to enter the menu.
3. Press
SET
and
u
or
d
until the correct numerical setting displays. Press
SET
to accept the new
value.
4. Repeat step 3. for ALPHA and DELTA.
5. Press
EXIT
to show the displayed temperature.
Accuracy and Repeatability
Compare the error observed at each calibration point with the Product accuracy specification to
determine accuracy performance. If the Product is adjusted, repeat the calibration procedure to verify
accuracy performance at all required temperature points. Repeatability can be verified by repeating a
temperature point, preferably one that is at the midpoint of the desired operating range, by first
measuring it in a sequence as temperature increases then measuring it again as temperature
decreases from the maximum operating temperature. The difference between the upward
measurement and the downward measurement is an indication of repeatability.
a
T
delta
T
T
1
1
1
1
100
1
100
= +
⎡
⎣⎢
⎤
⎦⎥
−
⎡
⎣⎢
⎤
⎦⎥
a
T
delta
T
T
3
3
3
3
100
1
100
= +
⎡
⎣⎢
⎤
⎦⎥
−
⎡
⎣⎢
⎤
⎦⎥
rzero
R a
R a
a
a
3 1
1 3
1
3
alpha
R
R
R a
R a
=
−
=
1
3
3 1
1 3
