DM-3100N Murata Digital Panel Meter

The Murata / Datel DM-3100N Digital Panel Meter uses solid-state self-illuminated, light-emitting diode (LED) displays. Their large size (0.56" high) and brilliant red light make them easily readable from many feet away. This DPM is contained in a compact low profile case which makes for higher packing density on test panel faces. Besides measuring DC voltages, components can be internally installed by the user to make resistance and current readings. The decimal point can also be externally selected by jumpering appropriate pins.

The versatility of this meter is further enhanced by its auto-zeroing capabilities, or if the customer desires, a pot can be internally installed by the user so that an offset can be obtained with a zero input to the meter, or a zero reading with an offset input.

The Murata / Datel DM-3100N Digital Panel Meter accepts a DC or slowly-varying input voltage between ±1.999V and displays that input on front panel numerical indicators. It employs a conventional dual-slope A/D converter plus (7) segment display decoder-drivers all in one LSI microcircuit. Since this microcircuit requires approximately 10V to power the A/D section, an internal DC/DC converter generates -5V from +5V power input to form a bipolar supply.

Open PC board pads are featured on the DM-3100N to accept user-supplied input voltage attenuators, current shunts, digital ohmmeter components, or an offset pot for applications such as 4-20 mA process control measurement.

Another feature of the DM-3100N is that a balanced differential input is used. When used with bridge or transducer inputs, it offers high noise immunity and can accurately measure very small signals in the presence of much larger common mode signals. Another characteristic of this balanced differential input is that is will not load down sensitive input circuits, due to its high input impedance, 100 megaohms, and low 5 pA bias current.

A very noteworthy feature of this meter is that it can be operated ratiometrically. This means that it has internal circuits that can automatically compensate for reference drifts in the supplies of balanced bridge or transducer sensors.

The DM-3100N finds use in analytical instruments, industrial process controllers, portable diagnostic instruments, automatic test equipment, medical and patient monitoring instruments, airborne, marine and ground vehicles, and data acquisition/data logging systems.