Proper sensor type is also a very important factor to obtain precise
measurements. The sensor must have the correct temperature range
to meet the process requirements. In special processes the sensor
might need to have
additional options
such as leak-proof, anti-
vibration,
be un-grounded or have special sheath materials
.
Standard sensor limits of error are +/-4 degrees F (+/- 2 degrees C )
or 0.75% of sensed temperature (half that for special ) plus drift
caused by improper protection or an over-temperature occurrence.
This error is far greater than controller error and cannot be corrected
on the sensor except by proper selection and replacement.
2-6 Sensor Input Wiring
18
4
19
5
20
6
4000 Series
8000 Series
6000 Series
PTA
TC+, V+
PTB, mA+
TC-, V-
PTB, mA-
B
B
A
RTD
_
_
+
+
V
V
_
+
TC
V mA RTD
Figure 2.8
Sensor Input Wiring
2-7 Control Output 1 Wiring
3
4
4000 Series
8000 Series
6000 Series
9
10
LOAD
LOAD
120V/240VAC
Mains Supply
Figure 2.9
Output 1 Relay or Triac (SSR) to Drive Load
PTA
TC+, V+
PTB, mA+
TC-, V-
PTB, mA-
External Device
25
