Bar-graph meters

A cheap, simple kind of meter can be made using a string of light-emitting diodes (LEDs) or a liquid-crystal display (LCD) along with a digital scale, to indicate approximate levels of current, voltage or power. This type of meter has no moving parts to break, just like a digital meter. But it also offers the relative-reading feeling you get with an analog meter.
Figure below is an example of a bar-graph meter that is used to show the power output, in kilowatts, for a radio transmitter. It indicates 0.8 kW or 800 watts, approximately.

34


The chief disadvantage of the bar-graph meter is that it isnโ€™t very accurate. For this reason it is not generally used in laboratory testing. The LED or LCD devices sometimes also flicker when the level is โ€œbetweenโ€ two values given by the bars. This can be annoying to some people.

Leave a Comment

error: Content is protected !!