Analog Devices AN531 Application Notes

AN-531

a

One Technology Way • P.O. Box 9106 • Norwood, MA 02062-9106 • 781/329-4700 • World Wide Web Site: http://www.analog.com

APPLICATION NOTE

5B37 Transfer Function

Calculating the Output Voltage of a 5B37 Signal Conditioner

The output voltage of a 5B37 thermocouple signal con­ditioner can be calculated by knowing: (a) the thermo­couple input voltage at the measurement temperature;
(b) the thermocouple input signal at the minimum point
of the 5B37 module temperature range; and (c) the 5B37
gain.

Transfer Equation for 5B37

To determine the output voltage from a 5B37 module,
use the following equation:

V

= (

TC Output

OUT

where,

1.

V

is the 5B37 module output (in volts).

OUT

2.TC

Output

is the thermocouple output voltage (in

mV) at the temperature being measured.

–

V

ZERO

) ×

GAIN

Table I provides the thermocouple output voltage at the
minimum temperature span of each 5B37 module
(V

) and the 5B37 gain.

ZERO

Sensors Software Program

For assistance in determining a specific thermocouple
output voltage at any temperature, you may contact
Analog Devices, Inc., and request a copy of the SEN­SORS software program. Alternatively, you may down­load this program from the Analog Devices World Wide
Web Site. This Windows
provides a convenient reference to look up tables of
temperature sensing devices, including thermocouples,
RTDs (Platinum, Nickel and Copper), as well as ther­mistors. Functions are implemented in both direc­tions (i.e., temperature-to-mV and mV-to-temperature),
as well as in both °C and °F.

®

3.1, 95, NT software program

E3281–5–3/98

3.

V

is the thermocouple output voltage (in mV) at

ZERO

the minimum temperature span specified for the
5B37 module.

4.

GAIN

is the throughput gain (in V/mV) of the 5B37

module.

Table I. Transfer Functions for Model 5B37 Thermocouple Signal Conditioner

Parameter 5B37-J-01 5B37-K-02 5B37-T-03 5B37-E-04 5B37-R-05 5B37-S-05 5B37-B-06 5B37-N-08

Temp (°C) Low –100 –100 –100 00000
Range High 760 1350 400 900 1750 1750 1800 1300

V

(V)Low00000000

OUT

Range High 55555555

(mV) Low –4.632 –3.553 –3.378 00000

V

IN

Range High 42.922 54.125 20.869 68.783 20.878 18.504 13.585 47.502
VIN Span (mV) 47.554 57.678 24.247 68.783 20.878 18.504 13.585 47.502
Gain (V/mV) 0.105143 0.086688 0.206211 0.072692 0.239486 0.270211 0.368052 0.105258
V

(mV) 4.632 –3.553 –3.378 00000

ZERO

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