Cooper Instruments & Systems DCM 437 Current Bridge Amplifier User Manual
Page 3
CF 27
3
4/2001
Specifications
Output Current Span
4 to 20 mA; 0 to 20 mA
Input for 16 mA Span
3 mV to 62 mV
Zero Adjust
12 mA
Temperature Coefficient
0° to 55°C
1 microamp/°C typical
4 microamp/°C maximum
Hysteresis
50 microamp maximum
Amplifier
Cell Sensitivity
(10 Volts Excitation)
0.3 mV/V to 6.2 mV/V
Linearity
0.005% typical
Temperature Stability
50 ppm/°C
Hysteresis
0.1% of span maximum
Input Bias Current
150 pA maximum
Input Noise: DC to 10 Hz
4 microvolts P-P maximum
Common Mode Input
0 to +7.5 Volts
Common Mode Rejection
DC to 60 Hz
90 dB minimum
Output
Current
0 to 20 mA
Loop Resistance
0 to 1000 ohm
Compliance
20 Volts maximum
Frequency Response
10 Hertz, 2 Pole Filter
Response Time to 0.1%
90 ms typical
Bridge Excitation Supply
Adjustment Range
5 to 15 Volts
Load Current
150 mA maximum
Stability 100
ppm/°C
maximum
Hysteresis 0.1%
Bridge Balance Adjust- (Tare Weight)
With 350 Load Cell
3mV/V Sensitivity
± 68% of Full Scale
Power Requirements
Input power supply is DC isolated from the amplifier and is reverse polarity protected.
Input Voltage
10 to 36 Volts DC
Input Current
with 150mA B+ load
with one 350 ohm Bridge
0.17A @ 36V to 0.7A @10V
0.1A @ 36V to 0.35A @10V
120 Hertz Ripple allowed
on input supply
1 Volt P-P at 10 Volts input
2 Volts above 12 Volts input
Isolation
700 Volts DC & .0033 mF
NOTE: Specifications apply 0°C to 55°C and 10 to 36 Volts DC input.
Getting Started with the Model DCM 437
This procedure is for large tare weights, i.e. greater than about 10% of the cell’s full scale rating.
I. Hook Up Procedure
A. Connect the + out of your load cell to the + INPUT, pin 10.
B. Connect the - out of your load cell to the - INPUT, pin 9.
Note: If the ±SENSE are not used in your application, the connections in step C & D need to be followed. If the
± SENSE are going to be used, do not jumper them as described in steps C & D.
C. Connect +Excitation, pin 6, to the + excitation of your load cell and jumper the + SENSE, pin 5, to
+Excitation, pin 6.
D. Connect -Excitation, pin 4, to the - excitation of your load cell and jumper the - SENSE, pin 3, to -Excitation,
pin 4.