background image

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.

 

Operation and accuracy with ac inputs above or below this range are not specified. 
Operation from waveforms other than sine waves is limited to 120Vrms. See Technical 
Note 1 for additional information.

Performance/Functional Specifi cations

Typical at Ta = +25°C, Vin = 250Vac / 60Hz sine wave, unless 
otherwise noted

AC Input (TB1)

Voltage Range 

85 to 264Vac (45-65 Hz)

Current Consumption

250Vac/60Hz: 12mA (max.)

UL/IEC61010-1

Measurement Category II

Performance

Sampling Rate

2-3 readings/second

Resolution

0.01Hz

Accuracy @ +25°C

±0.01Hz (typ.), ±0.02Hz (max.)

Temperature Drift

±0.0005Hz/°C (–25 to +60°C)

Mechanical

Dimensions

1.5" diameter x 1.1” depth
(38 x 28mm)

Display Type

Four digit, LED, 0.30” high (7.6mm)

Weight

0.9 ounces (25.5 grams)

Case Material

Polycarbonate

Terminal Block Torque

2.2 lb·in (0.25 N·m) ±20%

Wire Size And Type

18-22AWG (0.83-0.33mm

2

) copper, 

solid or stranded

Wire Insulation Strip Length 0.25" (6.4mm)

Environmental

Operating Temperature

–25 to +60°C

Storage Temperature

–40 to +75°C

Humidity (non-condensing)  0 to 85%

Ordering Information

DMR20-1-FM-R-C

85 to 264Vac frequency monitor (Red LED)

Knockout Punches

DMR20-1-KP

1.2" (30.5mm) Round knockout punch 
(no keying notch)

DMR20-2-KP

1.2" (30.5mm) Round knockout punch 
(with four keying notches)

DMR20-3-KP

1/8" and 3/16" (3.2 and 4.7mm) 
key-notch nibbler tool

Note: An M30 x 1.5 nylon hex nut and EPDM sealing gasket are supplied with each 
meter. The “-C” suffi x denotes RoHS compliance.

www.murata-ps.com

www.murata-ps.com/support

For full details go to

www.murata-ps.com/rohs

 

DMR20-1-FM

Self-Powered, 

LED Display, AC Line Frequency Monitor

MPM_DMR20-1-FM.A02 

Page 1 of 3

NANO

FEATURES

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

E156931

Отзывы: