MM4001 &
MM4001ISO
RTD INPUT
TRANSMITTERS
DESCRIPTION
The MM4001 modules are used to provide
an output voltage or current proportional
to an RTD input signal. It is useful in
measuring temperatures with a variety
of RTD materials.
The module utilizes a single constant-
current source to excite the RTD and
also has an accurate and stable leadwire
compensation circuit for compensating
3-wire RTDs against leadwire effects.
The MM4001ISO utilizes pulse width
modulation to develop a pulse train with
a duty cycle proportional to input signal
amplitude. This pulse train is coupled
through a pulse transformer where the
duty cycle data is converted to a
proportional DC level in the output circuit.
OPTIONS
The following options are available on the
MM4001 & MM4001ISO:
U
All circuit boards conformal coated for
protection against moisture.
DC Power
Inverter-isolated 12 V or 24 V DC
power.
CONTROLS
Two controls, ZERO and SPAN, are
accessible from the top of the module.
CALIBRATION
The MM4001 modules are shipped
precalibrated, if there is a need to
recalibrate, proceed as follows:
Refer to the instrument's label to determine
your instrument's supply voltage and input
and output ranges. Refer to the "Block
Diagram and Pin Connections" for pin
connections.
Connect a precision decade resistance,
potentiometer or RTD simulator to the
input. To avoid errors due to the
resistances of the connection wires,
use a three-wire connection as shown
in the “Block Diagram and Pin
Connections”. Connect a precision DC
voltage or current meter to the output.
Set the input resistance to the low end of
the input range and adjust the ZERO
control for the low-end output voltage or
current. Increase the input resistance to
full scale and adjust the SPAN control for
the full-scale output. Repeat until both
readings are correct.
CASE DIMENSIONS
INCHES [mm]
MOUNTING
The module is designed to plug into a
standard 8 pin relay socket. (MP008) is a
molded plastic socket that can be mounted
on a flat surface or snapped into 2¾ inch
wide PVC track (TRK 48).
A spring hold-down clip (CLP1) is avail-
able for installations where vibration may
be a problem.
A DIN-rail mounted socket (DMP008) is
available for 35mm symmetrical rail.
A Killark HK Series explosion-proof hous-
ing with dome and 8-pin socket is
available(HKB-HK2D-8).
WARRANTY
The Mighty Module Series of products
carry a limited warranty of 10 + 5 years.
In the event of a failure due to defective
material or workmanship, during the 10
year period, the unit will be repaired or
replaced at no charge. For a period of 5
years after the initial 10 year warranty,
the unit will be repaired, if possible, for a
cost of 10 % of the original purchase
price.
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