Self-Powered LED Meter Display

Murata Power Solutions
Part Number Information
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DMR20-1-FM Buy Now

Murata Power Solutions’ new DMR20-1-FM is the world’s smallest, self-powered, ac line frequency monitor. Simply connect 85 to 264Vac (45-65Hz) power and the meter is fully operational—no additional components are required. The unit can also measure distorted 120Vrms power sources with triangle and square waveforms, as well as quasi sine wave outputs of dc to ac power inverters.

An ultra-stable, quartz-crystal controlled microprocessor provides accuracies of ±0.02Hz over the operating temperature range of -25 to +60°C. DMR20-1-FM frequency moni-tors feature a large, 0.30”/7.6mm, bright LED display that can be easily read from 10 feet away (3 meters). A built-in resettable fuse and out-of-range indication assures long term reliability.

The DMR20-1-FM is housed in a rugged, round polycarbonate case that provides excellent protection against moisture, dust, shock and vibration. Panel installation is straightforward: using available tooling, simply drill and punch a 1.2 inch (30.5mm) diameter hole and anti-rotation notch, insert the meter and gasket, and securely fasten the meter using the supplied hex nut. The nut and gasket are designed to provide moisture ingress protection to IP67/NEMA 6.

DMR20-1-FM is exactly the same size as Murata Power Solutions’ DMR20-1-ACV (ac volts), DMR20-10-DCM (dc volts), and DMR20-1-TMP (temperature) digital panel meters.


  • Self-powered from 85 to 264Vac/45-65Hz supplies
  • 0.01Hz resolution & quartz crystal accuracy and stability
  • Installs in “oiltight” 1.20 inch (30.5mm) round cutouts
  • Four-digit LED display with out-of-range indication
  • Digital replacement for analog panel meters
  • Self-resetting internal fuse for long-term reliability
  • Supplied with EPDM rubber gasket and plastic hex nut
  • Provides moisture ingress protection to IP67/NEMA 6
  • Screw-style input terminal block simplifies installation
  • Knockout punches and tooling available
  • Approvals to UL/cUL/IEC/ 61010-1