Technical term needed

A decibel meter, aka db meter. Said to be "about $50 on ebay" but not by me.

GWE

This is not a question with an easy answer. The decibel is a relative measure, i.e., it is the ratio of two power levels expressed as a logrithm (dB = 10 log P1/P2). Sometimes, sound levels are measured in decibels referenced to the threshold of audibility. Commonly, radio frequency power is expressed in decibels referenced to a milliwatt (dBm) or to a watt (dBW). Antenna gain is expressed in dB referenced to the performance of an isotropic antenna. If the impedences are constant, since P = E squared / Z, decibels can express the ratio of two voltages (dB = 20 log E1/E2). Hence, the signal level into a receiver is often expressed as decibels referenced to a microvolt (dBuv). The list goes on and on...

And a wide variety of instruments are used to make the various measurements.

Jerry

"SteveB" wrote: What is the name for the electronic device that measures decibel levels? ^^^^^^^^^^^^^ The commonly used term that I know is "sound level meter."

On Sat, 5 Mar 2005 16:10:26 -0800, the inscrutable "SteveB" spake:

Those at Rat Shack are called "sound level meters".

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Nice answer to an indepth question, Jerry.

Sonometer?

WHAT????

"Tom Gardner" wrote: WHAT???? ^^^^^^^^^^^^^ Well, then how about "belweather?"

It's true you could use a yardstick and measure two distances, so it would be 20log(10)d1/d2 to give distance, say, measured in dB form. Or weight, with a scale. Or a simpson meter measuring some dc voltage.

But I think he was probably after a 'sound power level meter' even though he didn't come right out and say 'sound' in his question. :^)

Jim

Are you measuring voltage or sound ? - db is a measurement of 'pressure'... dbA

Be sure you know what type you are looking for.

Martin

SPL meter. (stands for Sound Pressure Level Meter)

They come in all sorts and functions. As cheap and limited as Radioshack meters with just A and C weighting, or as expensive as as Bruel & Kjers or Terrasondes with direct reference to ANSI standards, frequency bands, time measurement options, interchangeable microphones, etc....

If you are a neofite and just need an approximate reading, the Radioshack will do fine. If you need something that will hold up in court then hire an acoustician. He/she will come equipped with appropriate measurement system.

cheers T. Alan