Datasheet

9
®
ISO122
10.0V
Thermocouple
REF
102
27kΩ
R
1
R
4
+In
–In
–15V
2
14
13
1
R
G
12
10
3
5
4
11
R
5
R
3
R
2
Isothermal
Block with
1N4148
(1)
Ground Loop Through Conduit
100
Zero Adj
R
6
50Ω100Ω
+15V
+15V –15V +15V –15V
1
2
9
8
16
15
10
7
V
OUT
ISO122P
FIGURE 6. Thermocouple Amplifier with Ground Loop Elimination, Cold Junction Compensation, and Up-scale Burn-out.
SEEBACK
ISA COEFFICIENT R
2
R
4
TYPE MATERIAL (µV/°C) (R
3
= 100Ω)(R
5
+ R
6
= 100Ω)
Chromel
E Constantan 58.5 3.48kΩ 56.2kΩ
Iron
J Constantan 50.2 4.12kΩ 64.9kΩ
Chromel
K Alumel 39.4 5.23kΩ 80.6kΩ
Copper
T Constantan 38.0 5.49kΩ 84.5kΩ
NOTE: (1) –2.1mV/°C at 2.00µA.
1MΩ
INA101
2
6 4
+15V
0.01µF
6
5
RTD
(PT100)
1mA
1mA
2mA
R
2
= 2.5kΩ
–V
0V-5V
+V
Gnd
–V
S
= –15V
on PWS740
4-20mA
ISO122P
3
2
14
9
8
2
11
8
7
4
3
V
OUT
10
7
12
4
10
XTR101
+V
S
=15V
on PWS740
R
1
= 100Ω
10
11
5, 13
15
16
15
16
1
FIGURE 7. Isolated 4-20mA Instrument Loop. (RTD shown.)
R
S
RCV420