DESCRIPTION
The MM4431 raises its input to a power and
provides an output voltage or current pro-
portional to that power function (Y = X
m
). The
exponent M can be a value between 0.2 and
5. This range covers the most common
requirements for measuring differential pres-
sure in flow applications such as encoun-
tered in orifice plate or pitot tubes.
The range of M also includes the ranges used
to provide flow data from Parshall flumes and
V-notch weirs. In a Parshall flume, the flow
is related to the height of the liquid level by the
3/2 power of the height. In a V-notch weir,
flow is related by the 5/2 power to the liquid
height.
The MM4431 uses a complex integrated
circuit to find the exponent of the input
signal. The exponent is chosen by the choice
of two precision resistors and allows the unit
to be factory-scaled for a wide selection of
exponent values.
The following tables show the input/output
relationship for square root, using 4-20 mA
inputs and outputs.
MM4431
DC INPUT
POWER FUNCTION
EXPONENTIATOR
TRANSMITTER Y=X
m
OPTIONS
The following options are available of the
MM4431:
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 available
at the top of the module. The exponent, M,
is not adjustable
SPECIFICATIONS
Input Impedance
Voltage
100K
Current
1.25V drop std at 20 mA,
others available
Output Limits
Voltage
-10 to +15 V, 10 mA
Current
50 mA, 24V compliance
Accuracy
0.4
£
M
£
4
±0.15% of span
Isolation
Input/Output
greater than 500 megohms
1000 VAC rms
Temperature Stability
±0.04% of span per ° C
Common Mode Rejection
100 dB, DC to 60 Hz
Temperature, Operating
0 ° C to 60 ° C
32 ° F to 140 ° F
POWER
(2.5 MAX)
115 VAC ±10%, 50 or 60 Hz
230 VAC ±10%, 50 or 60 Hz
(DC Power Option)
12 VDC (limits 10 VDC to 15 VDC)
24VDC (limits 21 VDC to 32 VDC)
CALIBRATION
The MM4431 is 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, exponent
(M), and input and output ranges. Refer to
the "Block Diagram and Pin Connections" for
pin connections.
Connect a precision DC voltage or current
source to the input. Connect a precision DC
voltage or current meter to the output.
Set the input to the low end of the input range
and adjust the ZERO control for the low-end
output voltage or current. Increase the input
to full scale and adjust the SPAN control for
the full-scale output. Repeat until both read-
ings are correct.
MOUNTING
The module is designed to plug into a standard
8-pin relay socket.
MP008
is a molded plastic socket suitable for
mounting on a flat surface or in a 2 3/4 inch
wide PVC snap track
TRK48
. Socket
DMP008
is a 8-pin DIN rail mounted socket.
Use
CLP1
hold-down clip if needed for
vibration environment (
MP008
only). A
Killark HK Series explosion-proof housing
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.
Relays are not covered by the warranty.
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