Page 36 · 5400 Series
TECSource
User’s Manual
The
TECSource
automatically determines which equation to use based on the
conditions at the time of the measurement.
2-Wire versus 4-Wire Measurements
One concern in using RTDs are their relatively low resistance (typically 100
Ω
at
0°C), and small
Ω
/°C. Because of these two factors, the resistance of the cable
used to connect to the sensor can become a significant error in the sensor
measurement. The
TECSource
offers two RTD measurement modes: a
conventional two wire measurement mode, which is subject to this error, and a
four wire measurement mode that uses separate sensor and source lines to
remotely sense the actual resistance of the RTD and eliminate the cable or
connector resistances.
When using 4-wire measurement mode (only supported by sensor 1), you must
select
RTD (4-wire)
as the sensor type, and then connect the and
Remote at one side of the RTD, and Sensor– and Remote Sensor– to
the other side of the RTD. Make these connections as close to the sensor as
possible.
The drawings below illustrate how 2-wire and 4-wire connections work. Note that
4-wire measurements require all four wires to be brought through the cable to
the mount.
RTD 2-wire Measurement
RTD 4-wire Measurement
5400
RTD
Sensor
Remote
Remote Sensor–
Sensor–
Mount
Mount
5400
RTD
Sensor
Sensor–
Summary of Contents for TECSource 5400 Series
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