Digital panel meter

= Digital Panel Meter =

Digital panel meters are used to display an input signal, and measure current, voltage, and frequency. They are equipped with bright LED displays for display only or set point control options. Many panel meters also include alarm options as well as the ability to connect and transfer data to a computer.

Since panel meters are generally mounted inside an instrument panel, the panel must be cut to accommodate the panel meter. In order to provide interchangeability between panel meters, most panel meters are designed to standard DIN sizes. Large display panel meters are commonly used when the display must be visible at a distance.

Benefits & Applications:
• Accuracy is typically .5% or better
• Monitors and measures voltage and current
• Large digital displays for AC & DC application
• External or loop power required

In the past, most measuring instruments utilized an analog panel meter in displaying the measured information. Analog panel meters are quite economical; however, the non-linearity in the analog meter movement can produce errors. In addition, analog panel meters have reading errors and parallax problems. Due to the small size of the meter screen, analog panel meters are hard to accurately read. One benefit of a digital panel meter is that it provides a high level of accuracy and can be easily read with little or no ambiguity in the reading. A digital panel meter is provided with an LED display of certain digits corresponding to the length of output parameters. Some digital panel meters can be calibrated to read out in any desired dimensional units.http://www.electronics-manufacturers.com/products/electrical-electronic-components/digital-panel-meter/] >Electronics Manufacturers]

Designed for process signals such as 4-20 mA and 0-5 or 0-10 V that require zero and span adjustment, Laureate Model P has display that can be scaled to 5 full digits from front panel to read in engineering units such as psi or gpm. It features programmable adaptive moving average noise filter and built-in, isolated excitation supply with selectable 5, 10, and 24 Vdc output levels to power 2-wire, 4-20 mA transmitters.http://findarticles.com/p/articles/mi_m0PIL/is_2007_May_7/ai_n19054401] >Product News Network]

One digital panel meter can be made to display several stored input voltage values being held by a voltage hold signal.http://www.bioe.umd.edu/~artjohns/publications/instrumentation.html] >The Fischell Department of Bioengineering * A. James Clark School of Engineering]

A fast acting digital panel meter, which can measure and store the peak value of an impact force, has just been released by London Electronics. The idea for the new panel meter began when a manufacturer of body armour for the forces had an unusual request. The company wanted to clearly demonstrate the resilience of its product in a dramatic way. In a mock attack, a hammer wielding assailant would try his best to overcome a member of staff protected by the body armour. The hammer contained a force transducer, which generated a fleeting signal, proportional to the force of the blow. This signal was connected to the new panel meter, which displayed the peak impact force, and stored the value in memory. Because the peak signal is present for a fraction of a millisecond, and an accuracy of better than 0.5% was required, London Electronics had to design a novel fast-acting peak detector system. The system was a success, no-one got hurt and the manufacturer was able to prove the effectiveness of its armour. Because there are many other similar applications in the testing industry, particularly in destructive testing, London Electronics has developed the fast acting panel meter to accept loadcell signals and load amplifier output signals such as 4-20mA and 0-10V.http://www.engineeringtalk.com/news/lel/lel107.html] >Engineering Talk]

Common manufacturers include:
• Yokogawa
• Simpson
• Crompton
• Texmate
• Laurel
• Datel

Patents
There are patents for certain digital panel meters including:
Patent number: 4157501http://patft.uspto.gov/netacgi/nph-Parser?Sect2=PTO1&Sect2=HITOFF&p=1&u=%2Fnetahtml%2FPTO%2Fsearch-bool.html&r=1&f=G&l=50&d=PALL&RefSrch=yes&Query=PN%2F4157501] >US Patent website]
Filing date: Jan 23, 1978
Issue date: Jun 5, 1979
Inventors: Ralph E. Cain, Jr., Thomas J. Crowell
Assignee: R. T. Engineering Service Inc.
Primary Examiner: Ernest F. Karlsen
U.S. Classification
324/115; 324/119; 324/123R; 324/156
International Classification
G01R 1512; G01R 1922; G01R 130
Drawings available http://www.google.com/patents?id=Tf13AAAAEBAJ&printsec=drawing&zoom=4&dq=digital+panel+meter] >Google Patent website]

Digital panel meters are available from:
Precision Digital Corp.
Martel Meters
WEI Online - [http://www.weionline.com/digital_panel_meters.php]
Red Lion
Otek Corp.

References: