OsTech Laser Lab Source LDC Series, Руководство по эксплуатации

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6.2 Temperature sensor
The default coefficients c
0
, c
1
, c
2
and c
3
of this polynomial correspond to an
NTC with 10 k Ω at 25 ◦ C which is a wide spread standard. You may adjust these
coefficients to a different sensor by the commands x
TSC
[
0
. . .
3
].
Additionally, the driver can be set to calculate the temperature using the following
third-order polynomial:
T
(
V
) =
c
3
· V
3
+
c
2
· V
2
+
c
1
· V
+
c
0
(
TSM0
)
The model switching is done with the x
TSM
command. Here, x
TSM0
causes the
polynomial model to be used and x TSM1 switches to the Steinhart-Hart equation.
The coefficients for some common sensors are given in the table below.
The settings for a PT100 or PT1000 sensor can be calculated from its resistance
using the following formulas:
R
0
=
100 Ω (at 0 ◦ C)
R
(
T
) =
R
0
·
(
1
+
A · T
−
B · T
2
)
( T : temperature in
◦
C)
As B is commonly neglected you can calculate them using
R
(
T
) =
R
0
·
(
1
+
A · T
)
and using the divider network wich leads to the coefficients shown in the following
table:
x
TSC0
x
TSC1
x
TSC2
x
TSC3
polynomial model (x TSM0 )
NTC 10 kW B3980 135.83
−
63.2256 15.3332
−
1.80043
NTC 10 kW B3450 156.089
−
74.4317 17.5466
−
1.99111
PT100 TK3850
−
266.475 2330.44 0 0
PT1000 TK3850
−
327.084 344.924 0 0
AD590 (1 µA/K)
−
897.065
−
234.043 0 0
Steinhart-Hart equation (x TSM1 )
NTC 10 kW B3980
−
273.15 1.0832 · 10
−
3
2.4141 · 10
−
4
6.505 · 10
−
8
NTC 10 kW B3450
−
273.15 1.1293 · 10
−
3
2.3411 · 10
−
4
8.7755 · 10
−
8
The settings for the AD590 (1 µA/K) sensor can be calculated using
U
(
T
) =
U
ref
− (
4272.72 · 10
−
6
· T
)
( T : temperature in ◦ C)
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