ThermoWorks 9103 HART SCIENTIFIC FIELD DRY-WELL TEMPERATURE CALIBRATORS - Manual (Page 42)

B T T
= −
3 2
C
T T T T
= ⎡
⎣⎢
⎤
⎦⎥
−
⎡
⎣⎢ ⎤
⎦⎥
− ⎡
⎣⎢
⎤
⎦⎥
−
⎡
⎣⎢ ⎤
⎦
4 4 3 3
100
1
100 100
1
100 ⎥
D
T T T T
= ⎡
⎣⎢
⎤
⎦⎥
−
⎡
⎣⎢ ⎤
⎦⎥
− ⎡
⎣⎢
⎤
⎦⎥
−
⎡
⎣⎢ ⎤
⎦
3 3 2 2
100
1
100 100
1
100 ⎥
E R R
= −
4 3
F R R
= −
3 2
delta
AF BE
DE CF
=
−
−
T
1-4
- Measured temperature using thermometer.
R
1-4
- Value of R from display of 9103 (Press SET and DOWN at the same
time.)
where
T
1
and R
1
are the measured temperature and resistance at –25°C
T
2
and R
2
are the measured temperature and resistance at 0°C
T
3
and R
3
are the measured temperature and resistance at 60°C
T
4
and R
4
are the measured temperature and resistance at 125°C
10.2.2 Compute R0 and ALPHA
a T delta
T T
1 2
2 2
100
1
100
= +
⎡
⎣⎢ ⎤
⎦⎥
−
⎡
⎣⎢ ⎤
⎦⎥
a T delta
T T
3 4
4 4
100
1
100
= +
⎡
⎣⎢ ⎤
⎦⎥
−
⎡
⎣⎢ ⎤
⎦⎥
rzero
R a R a
a a
=
−
−
4 1 2 3
1 3
alpha
R R
R a R a
=
−
−
2 4
4 1 2 3
delta is the new value of DELTA computed above.
9103 Dry-Well
User’s Guide
40