2
1.3 General Description
The transmitter is normally powered by an unregulated power supply as
shown in
Figure 1-1
. The proportionally-transmitted signal begins at 4mA,
at the low end of its temperature range, and increases to 20mA, at the
high end of its temperature range. (There are various temperature ranges
available for the transmitter. To order, refer to
Section 1.5
for correct
Model Numbers and Range Codes.)
Figure 1-1 RTD Transmitter
The transmitter works with 2 or 3-wire RTDs and provides an output
current of 4-20mA proportional to the RTD Sensor.
When the transmitter is mounted inside a protection head, (see
Figure 2-1
),
two copper wires now carry the temperature signal and dc voltage to
operate the transmitter, thereby reducing possible noise pick-up errors.
The transmitter does NOT provide isolation between its input and the
4-20 mA output. Note, however, that the RTD element is electrically
insulated.
1.4 Features
• +/-0.1% full-scale accuracy (with respect to the RTD input
resistance)
• 4-20 mA output
• Upscale break protection
• Low
Cost
FIELD
CONTROL ROOM
