®

INA120

10

INA120

REF102

R

80.6k

4

Ω

R

1M

7

Ω

R

5.23k

2

Ω

R

27k

1

Ω

R

100

3

Ω

1N4148

Cu

Cu

R

50

5

Ω

R

100

Zero Adj

6

Ω

V+

V

O

K

6

10.0V

4

(1)

(2)

(2)

FIGURE 7. Thermocouple Amplifier With Cold Junction Compensation.

Shielded Cable

FIGURE 8. Guard Drive Circuit.

A

3

A

1

A

2

1

18

2

12

7

6

3

4

5

8

9

10

11

17

13

16

15

14

V

IN

V+

INA105

V

O

G = 1000

1

3

6

5

2

V–

220

Ω

SEEBECK

ISA

COEFFICIENT

R

2

R

4

TYPE MATERIAL

(

(R

=100

E

Chromel

58.5

3.48k

56.2k

Constantan

J

Iron

50.2

4.12k

64.9k

Constantan

K

Chromel

39.4

5.23k

80.6k

Alumel

T

Copper

38.0

5.49k

84.5k

Constantan

NOTES: (1) –2.1mV/

°C at 200µA.

(2) R

indication.