Operation
PT12
Manual
7/20/2021
Page
27
of
48
4.4.3
COEFFICIENT
MODE
The
PT12
currently
supports
both
Callendar
‐
Van
Dusen
(CVD)
and
ITS
‐
90
for
calculating
temperature.
Each
probe
may
be
configured
independently.
If
using
a
smart
probe,
the
coefficients
may
be
stored
on
the
probe
itself.
Only
one
coefficient
type
may
be
used
at
a
time
to
measure
temperature,
but
both
coefficient
types
may
be
stored
on
the
probe
(if
a
smart
probe)
or
in
the
system
(if
a
basic
probe).
CALLENDAR
‐
VAN
DUSEN
(CVD)
To
select
CVD
mode,
tap
the
coefficient
mode
drop
down
and
select
CVD.
In
CVD
mode,
the
PT12
calculates
temperature
from
resistance
by
solving
the
following
CVD
equation
for
temperature
(T)
:
When
T
<
0
°C
(or
R
<
R
o
)
𝑅
𝑅𝑜 ∗
1
𝐴 𝑇
𝐵 𝑇
𝐶 𝑇
100
𝑇
[1]
When
T
≥
0
°C
(or
R
≥
R
o
)
𝑅
𝑅 ∗
1
𝐴 𝑇
𝐵 𝑇
[2]
