5.2.1.5
Callendar-Van Dusen Conversion
EDIT SPRT 01
PROBE SER#: 1
CONVERSION: CVD
R0: 100.0
ALPHA: 0.00385
DELTA: 1.507
BETA: 0.111
The following equations are used for the Callendar-Van Dusen conversion:
r t C
R
t
t
t
t
R
( [
])
°
=
+
−
−
⎛
⎝⎜
⎞
⎠⎟
⎡
⎣⎢
⎤
⎦⎥
⎧
⎨
⎩
⎫
⎬
⎭
≥
0
0
1
100 100
1
0
α
δ
1
100 100
1
100
1
100
3
+
−
−
⎛
⎝⎜
⎞
⎠⎟ −
−
⎛
⎝⎜
⎞
⎠⎟
⎛
⎝⎜
⎞
⎠⎟
⎡
⎣
⎢
α
δ
β
t
t
t
t
t
⎤
⎦
⎥
⎧
⎨
⎪
⎩⎪
⎫
⎬
⎪
⎭⎪
≤
⎧
⎨
⎪
⎪
⎩
⎪
⎪
t
0
The user-defined parameters for the Callendar-Van Dusen conversion are R0
(R
0
), ALPHA (
α
), DELTA (
δ
), and BETA (
β
). The defaults are R0: 100.0,
ALPHA: 0.00385055, DELTA: 1.4998, and BETA: 0.109 which are applicable
with DIN-43760 or IEC-751 type RTDs.
Some probes may be provided with A, B, and C coefficients for the
Callendar-Van-Dusen equation in the following form:
(
)
(
)
[
]
r t
R
At
B
t
R
At
Bt
C t
t
t
( [
])
°
=
+
+
≥
+
+
+
−
≤
⎧
⎨
⎪
⎩⎪
C
0
2
0
2
3
1
0
1
100
0
The A, B, and C coefficients can be converted to
α
,
δ
, and
β
coefficients using
the following formulas:
α = +
A
B
100
δ = −
+
100
100
1
A
B
β = −
+
10
100
8
C
A
B
1560 Thermometer Readout
User’s Guide
38
