Mighty Module Model DIS878
Strain Gauge (Bridge) Input Process Indicator

Features

Description

The DIS878 provides a display, optional isolated DC output voltage or current proportional to the output of a strain gauge bridge, and optional alarm setpoints. The units include filtering and conditioning to reduce susceptibility to transients and noisy operations as well as a well regulated excitation voltage for the strain gauge and a high quality differential preamplifier to condition the low level output from the bridge.  The digital display utilizes an auto-zero dual-slope integrating A/D converter for accuracy and stability.

All controls are accessible by removing a gasketed front access panel. The display controls are wide ranging so that they can be calibrated to display engineering units. Decimal point selection is made with a switch, also accessible from the front. A complete set of engineering unit labels is sent with each DIS. Once the display has been adjusted to read the correct engineering units, the alarm setpoints can be adjusted without test equipment and without disturbing the output voltage or current.

Either setpoint may be displayed by use of the SP CAL switch.  Each setpoint has a red LED to indicate alarm status. The alarms have adjustable deadbands. Terminations are made to a screw terminal connector on the rear of the case.

Typical Applications

Weight and pressure indication, control, monitoring, data acquisition and warning.

Mounting

The DIS is designed to be mounted from the front of a panel through a standard horizontal 3.62 x 1.77 inches (1/8 DIN) cutout. Two mounting camscrews secure the DIS to the panel.

Specifications

INPUT SPAN 0.5 mV/V to 1 V/V IINPUT IMPEDANCE 200 kilohms EXCITATION fixed 10 V   40 mA max load EXCITATION STABILITY ±0.005%/ºC OUTPUT RANGE Voltage   select any range between ±10 V     10 mA max load     (min span 0.2 V) Current   select any range from 0 to 20 mA max     24 V compliance**     (min span 1 mA) RELAY CONTACTS (spdt) Resistive Load:   5 A max, 150 W max,   240 VAC max, 30 VDC max Inductive Load:   1/8 HP max at 120/240 VAC SETPOINT each alarm 0 to 100% of span DEADBAND 0.25% to 100% of span RESPONSE TIME 1 sec typical ISOLATION Output/Input   >500 megohms Breakdown Voltage   >600 VAC rms

DISPLAY Digit Size   .56 inch LED, 3 1/2 digits, ±1999 Decimal Point   ±1.9.9.9 Control Range   Zero     ±1999   Span     min span 10     max span 2000 Display Update   3/sec ACCURACY ±0.1% of span LINEARITY Display   ±0.01% of span Output   ±0.025% of span OUTPUT RIPPLE <0.1% of span   (peak to peak) COMMON MODE REJECTION 120 dB, DC to 60 Hz OPERATING TEMPERATURE  14ºF to 140ºF -10ºC to 60ºC TEMPERATURE STABILITY ±(0.02% of span +30 µV)/ºC max POWER 115 VAC ±10%, 50/60 Hz   (4 W max) 230 VAC ±10%, 50/60 Hz   (4 W max)

* Within specified range limits.

** Compliance:  The sum of the voltage drops in the output loop cannot exceed 24 V at rated current 
    (1200 ohms at 20 mA).