Specifications

Standard Thermocouples
I.SA. Type
Materials
Color Code
J Iron-Constantant (I/C)
White( + ) Red( - )
K Chromel-Alumel
Yellow( + ) Red( - )
T
Copper-Constanan
Blue( + ) Red( - )
Platinum-Platinum 13%Rhodium -
Platinum-Platinum 10% Rhodium
-
Wiring RTD Circuits
6275 units are designed for 100 Ohm Platinum RTD’s 2-wire RTD’s are
connected to terminals 1 and 2 with a jumper connecting 2 to 3. Keep leads
short and use heavy gauge copper extension wires if necessary, to minimize
lead resistance. For long runs 3-wire RTD should be used and wire gauge
should be sufficient that resistance does not exceed 10 Ohms. An error of
0.2ºF will result for each additional 10 Ohms Per lead
DO NOT RUN RTD LEADS IN IN THE SAME CONDUIT AS POWER LINES.
If shielded RTD wire is used, terminate the shield only at the controller end,
using the comer screw provided for that purpose.
NOTE RTDs tend to be shock sensitive and require extra care in handling
and installation.
THERMOCOUPLE PLACEMENT (or RTD)
Proper thermocouple placement can eliminate many problems in the sys-
tem. The probe should be placed so that it can detect any temperature
change with minimal thermal lag. In a process that requires fairly constant
heat output, the probe should be placed close to the heater. In processes
where heat demand is variable, the probe should be close to the work area.
Some experimenting with probe location is often needed to find its
optimum Position.
A WORD ON ELECTRICAL NOISE
Microprocessor are essentially small computers. As such they can
randomly be interferred with by large electrical spikes, even with elaborate
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