GW Instek GOM-802 - Measurement RTD Sensorstemperature; Optional Platinum Sensor

APPENDIX
49
RTD Sensors
Overview
Resistive Thermal Devices (RTDs) are commonly used as
temperature sensors. RTDs change resistance linearly over
a specific range of temperature. The table below shows
some of the inherent features of RTDs compared to
thermocouples.
Feature
Descri
p
tion
Accurac
y
Hi
g
her accurac
y
Resolution
0.1~1.0
˚
C, hi
g
her resolution
S
p
eed o
f
res
p
onse
Slower
Sel
f
-heatin
g
Yes
Lon
g
term stabilit
y
Good
Output characteristics
Approx. 0.4ohm/
˚
C, near
linear
Optional Platinum Sensor
Introduction
The optional platinum sensor is a PT-100 sensor.
The PT-100 sensor meets the German DIN43760:
1968 3 wire measurement specification.
These sensors are one of the most common
temperature sensors used in industry. These sensors
have a nominal resistance of 100
Ω at 0˚C.
The relationship between temperature and resistance
for the PT-100 sensor can be described with the
Gallendarvan Dusen equation shown below:
RRTD=R0[1+AT+BT
2
+CT
3
(T-100)]
W
here: RRTD is the calculated resistance of the
RTD.
R0 is the known RTD resistance at 0˚C.
T is the temperature in˚C
A=alpha [I+(delta/100)]
B=-I(alpha)(delta)(Ie-4)
C=-I(alpha)(beta)(Ie-8)
The Alpha (A), Beta (B), Delta (D) values for the