Sensor placement (thermocouple or rtd), Thermocouple wire identification – West Control Solutions Pro-EC44 User Manual
Page 18
Pro-EC44 2-Loop Graphical Profile Controller & Recorder
Pro-EC44 Product Manual - 59540-1 October 2013
Page 11
Sensor Placement (Thermocouple or RTD)
If a temperature probe is to be subjected to corrosive or abrasive conditions, it must be
protected by an appropriate thermowell.
Probes must be positioned to reflect the true process temperature:
1. In a liquid media - the most agitated area
2. In air - the best circulated area
CAUTION:
The placement of probes into pipe work some distance from the
heating vessel leads to transport delay, which results in poor control.
For a two wire RTD, a wire link should be used in place of the third wire (see the wiring
section for details). Two wire RTDs should only be used with lead lengths less than 3 metres.
Use of three wire RTDs is strongly recommended to reduce errors do to lead resistance.
Thermocouple Wire Identification
The different thermocouple types are identified by their wires colour, and where possible, the
outer insulation as well. There are several standards in use throughout the world, but most
regions now use the International IEC584-3 standard.
The table below shows the wire and sheath colours used for most
common thermocouple types. The format used in this table is:
THERMOCOUPLE WIRE COLOUR CHART
Type
International
IEC584-3
USA ANSI
MC 96.1
British
BS1843
French
NFC 42-324
German
DIN 43710
J
+
*
Black
Black
White
Black
Yellow
Black
Yellow
Black
Red
Blue
-
White
Red
Blue
Black
Blue
T
+
Brown
Brown
Blue
Blue
White
Blue
Yellow
Blue
Red
Brown
-
White
Red
Blue
Blue
Brown
K
+
Green
Green
Yellow
Yellow
Brown
Red
Yellow
Yellow
Red
Green
-
*
White
Red
Blue
Purple
Green
N
+
Pink
Pink
Orange
Orange
Orange
Orange
-
White
Red
Blue
B
+
Grey
Grey
Grey
Grey
Red
Grey
-
White
Red
Grey
R & S
+
Orange
Orange
Black
Green
White
Green
Yellow
Green
Red
White
-
White
Red
Blue
Green
White
C (W5)
+
White
White
-
Red
Note: * = Wire is magnetic
– a magnet can be used to assist with correctly
identifying the type and polarity of the conductors
+
Wire
Sheath
-
Wire