True-RMS self-powered AC voltmeter fits standard panel cutout

August 29, 2013 // By Graham Prophet
Murata's DMR20-1-ACV “nanometer” is a self-powered four-digit bright LED voltmeter. This line powered AC voltmeter can measure the true RMS value of its input from 85 to 264 VAC to within 0.1 V resolution.

Designed to be completely self-contained, the low cost two-wire voltmeter requires no additional components or connections apart from the AC voltage it is measuring. It is capable of accurately measuring quasi-sine AC source such as modified, modified 2-step and modified 3-step sine wave in addition to conventional sine, triangle and square wave inputs.

The voltmeter fits an industry standard “oiltight” 30 and 30.5 mm / 1.2 inch round panel cutout. The 7.6 mm / 0.3 inch four-digit LED display is housed in a rugged round polycarbonate case that provides protection against dust, moisture, vibration and shock. It is supplied with an EPDM rubber gasket and plastic hex nut that aid protection to IP67 / NEMA6 specification for water ingress.

The DMR20-1-ACV measures the AC line voltage of a wide range of applications such as primary line power, power distribution units and backup power generation sources. The voltmeter consumes a maximum of 30 mA when used at 250 VAC / 60 Hz. Round knockout punch tooling can be ordered with the DMR20.

Murata; www.murata-ps.com/data/meters/dmr20-1-acv.pdf

A 3D CAD model can be downloaded from: www.murata-ps.com/en/3d/meters.html