The DPM 970 is a digital AC voltmeter module in the DPM970 series. It has a maximum measurement voltage of 500V AC (2kV) and a maximum measurement current of 2mA. It can be used to measure most AC voltages and currents by changing the value of the scaling resistors or adding a shunt. The DPM 970 has auto-zero and DC offset voltage suppression features. The digital hold function freezes the last displayed reading. Calibration is achieved via two multi-turn potentiometers for offset and scale. Connection to the meter is via screw terminals. The module is housed in a robust carrier which can be bolted in place or panel mounted using the bezel, window and clips provided.
The DPM970 is a digital AC voltmeter module with a 19 mm (0.75") digit LCD, LED backlighting, true‑RMS measurement and a full‑scale range of 500 V RMS (2 kV RMS with external scaling). It offers features such as auto‑zero, digital hold, and calibration via multi‑turn potentiometers. The module is housed in a robust carrier that can be panel‑mounted using supplied bezel, window and clips.
The manual explains how to connect the module using screw terminals, adjust scaling resistors (RA1, RA2, RB) for different voltage/current ranges, and safely operate the device within the Low Voltage Directive limits. Safety warnings, dimension drawings, and wiring diagrams are included to aid installation and troubleshooting.
| Accuracy (overall error) | 1.5 % (+2 count) |
|---|---|
| Full scale reading | 0‑1999 RMS |
| Resolution | 1 VRMS |
| Sample rate | 3 samples/sec |
| Operating temperature range | 0 °C – 50 °C |
| Temperature stability | 200 ppm/°C |
| Frequency range (input voltage) | 15 Hz – 15 kHz |
| Input impedance (2 kV range) | 1 MΩ |
| DC supply voltage | 7.5 V – 14 V |
| Supply current (backlighting off) | 1.5 mA |
| Supply current (backlighting on) | 50 mA |
| Panel cut‑out | 72 mm × 40 mm |
| Maximum panel thickness | 3 mm |
The module can safely measure up to 500 V RMS across the ACV and COM terminals.
By altering the values of the scaling resistors RA1, RA2 and RB, or by adding external scaling resistors for higher ranges.
It freezes the last displayed reading so it remains on the screen indefinitely.
The DPM970 operates from a DC supply voltage between 7.5 V and 14 V.