db meter?
 

Anyone got a clean db meter they don't need and want to sell/trade? I live about
100 yards from a large freeway that the state is preparing to widen, and I want
to take some sound level data to feed to their team that's evaluating the need
for sound wall height adjustment. Also, I want to keep an "ear" on the sound
intensity levels reached in my son's band's practice space.

I know this isn't exactly on topic, but it's a damn sight closer than a lot of
the garbage I see lately, and I've been a regular on this NG since the mid-90s.

Thanks!

Grant Erwin
Kirkland, Washington

On Fri, 16 Sep 2005 07:49:42 -0700, Grant Erwin
wrote:

Anyone got a clean db meter they don't need and want to sell/trade? I live about
100 yards from a large freeway that the state is preparing to widen, and I want
to take some sound level data to feed to their team that's evaluating the need
for sound wall height adjustment. Also, I want to keep an "ear" on the sound
intensity levels reached in my son's band's practice space.

I know this isn't exactly on topic, but it's a damn sight closer than a lot of
the garbage I see lately, and I've been a regular on this NG since the mid-90s.

Thanks!

Grant Erwin
Kirkland, Washington

Radio Shack sells one for $60, claims accuracy of 2 dB at 114 dB.
It's pretty hard to measure sound pressure level more accurately than
that outside of an anechoic chamber.

http://www.tnt-audio.com/clinica/spl-meter_e.html

"Don Foreman" wrote in message
...
Radio Shack sells one for $60, claims accuracy of 2 dB at 114 dB.
It's pretty hard to measure sound pressure level more accurately than
that outside of an anechoic chamber.

$49 and change in our neck of the woods. And yes, it is pretty accurate...
or at least reproducible. We use ours to measure the sound pressure of
salutes. The digital version has a sample-and-hold feature we need for peak
readings.

LLoyd

Grant Erwin wrote:
Anyone got a clean db meter they don't need and want to sell/trade? I
live about 100 yards from a large freeway that the state is preparing to
widen, and I want to take some sound level data to feed to their team
that's evaluating the need for sound wall height adjustment. Also, I
want to keep an "ear" on the sound intensity levels reached in my son's
band's practice space.

I know this isn't exactly on topic, but it's a damn sight closer than a
lot of the garbage I see lately, and I've been a regular on this NG
since the mid-90s.

Thanks!

Grant Erwin
Kirkland, Washington

The measurements you are planning to take for the freeway people are not
easily done with a common sound level meter. The preferred method is to
measure LEQ ,the time averaged sound level, over a 24 hour period.
Usually another 8 hour LEQ measurement is taken during hours of sleep
for a residential community and then combined. Also the weighting of the
measurement (A,B or C) has to be taken in account. Sometimes frequency
specific measuremets are also taken.

Here is a very basic prediction of sound level attenuation for a wall
separating a sender from a receiver, if the receiver is much further
away from the wall then the sender.
Height of wall squared /( wavelenght of frequency, times ,distance from
wall to sender). This gives a number which then is plotted on an
estimating chart.
For a calculation result of .5 the attenuation is 5 db
For a result of 1 the attenuation is 10 db
For a result of 2 its 12db
For 4 its 16 db
For 6 its 18 db
For 10 its 20 db
For 20 its 23 db
For 30 its 25 db
For 100 its 30 db, and that is the theoretical limit. In practice more
than 25 db attenuation is unheard of.

cheers
T.Alan

I'm hearing (no pun intended) that if I want cheap buy the Rat Shack digital SPL
meter. I'll probably do that. And I'm not trying to really outdo a pro tester, I
just want some data when I go object to their not raising my sound wall. I know
a guy who did this a long time ago (he was one of my dad's coworkers) and he
used a handheld meter to get data from his front porch and he said it was very
effective at the time. Thanks to all.

GWE

T.Alan Kraus wrote:

Grant Erwin wrote:

Anyone got a clean db meter they don't need and want to sell/trade? I
live about 100 yards from a large freeway that the state is preparing
to widen, and I want to take some sound level data to feed to their
team that's evaluating the need for sound wall height adjustment.
Also, I want to keep an "ear" on the sound intensity levels reached in
my son's band's practice space.

I know this isn't exactly on topic, but it's a damn sight closer than
a lot of the garbage I see lately, and I've been a regular on this NG
since the mid-90s.

Thanks!

Grant Erwin
Kirkland, Washington


The measurements you are planning to take for the freeway people are not
easily done with a common sound level meter. The preferred method is to
measure LEQ ,the time averaged sound level, over a 24 hour period.
Usually another 8 hour LEQ measurement is taken during hours of sleep
for a residential community and then combined. Also the weighting of the
measurement (A,B or C) has to be taken in account. Sometimes frequency
specific measuremets are also taken.

Here is a very basic prediction of sound level attenuation for a wall
separating a sender from a receiver, if the receiver is much further
away from the wall then the sender.
Height of wall squared /( wavelenght of frequency, times ,distance from
wall to sender). This gives a number which then is plotted on an
estimating chart.
For a calculation result of .5 the attenuation is 5 db
For a result of 1 the attenuation is 10 db
For a result of 2 its 12db
For 4 its 16 db
For 6 its 18 db
For 10 its 20 db
For 20 its 23 db
For 30 its 25 db
For 100 its 30 db, and that is the theoretical limit. In practice more
than 25 db attenuation is unheard of.

cheers
T.Alan

On Fri, 16 Sep 2005 10:44:30 -0700, with neither quill nor qualm,
Grant Erwin quickly quoth:

I'm hearing (no pun intended) that if I want cheap buy the Rat Shack digital SPL
meter. I'll probably do that. And I'm not trying to really outdo a pro tester, I
just want some data when I go object to their not raising my sound wall. I know
a guy who did this a long time ago (he was one of my dad's coworkers) and he
used a handheld meter to get data from his front porch and he said it was very
effective at the time. Thanks to all.

Yeah, grab one off Ebay for less than half the new price, delivered.

I ended up buying that JOAT meter after all. (VOM, humidity, sound,
light, capacitance meter rolled into one rubberized case with nice
padded carrying case for $75 delivered. I haven't had a chance to
check the cal on it but it gives identical wall outlet readings to
my super-duper $5 HF/Chiwanese DVM.) I like it! Mastech S8209.

I keep forgetting to see how the dog barking registers on the meter
above the freeway noise but it cuts through walls and double-paned
windows like a hot knife through butter. The mutt has been fairly
quiet lately. I-5 runs downhill about 1/2 mile away from my house
and the truck traffic can be overwhelming sometimes. Especially when
a convoy of unmuffled jake brakes go by, all farting in unison.

--
The ancient and curious thing called religion, as it shows itself in the
modern world, is often so overladen with excrescences and irrelevancies
that its fundamental nature tends to be obscured.
--H.L. Mencken in "Treatise on the Gods"

Lloyd E. Sponenburgh wrote:
"Don Foreman" wrote in message
...

Radio Shack sells one for $60, claims accuracy of 2 dB at 114 dB.
It's pretty hard to measure sound pressure level more accurately than
that outside of an anechoic chamber.


$49 and change in our neck of the woods. And yes, it is pretty accurate...
or at least reproducible. We use ours to measure the sound pressure of
salutes. The digital version has a sample-and-hold feature we need for peak
readings.

LLoyd


Salutes.. fireworks?

John

Grant - those can be leased - you want a dbA for audio - Maybe there is a
leasing company that will 'dump' a unit due to downsizing.

Martin
Martin Eastburn
@ home at Lions' Lair with our computer lionslair at consolidated dot net
NRA LOH, NRA Life
NRA Second Amendment Task Force Charter Founder



Grant Erwin wrote:
Anyone got a clean db meter they don't need and want to sell/trade? I
live about 100 yards from a large freeway that the state is preparing to
widen, and I want to take some sound level data to feed to their team
that's evaluating the need for sound wall height adjustment. Also, I
want to keep an "ear" on the sound intensity levels reached in my son's
band's practice space.

I know this isn't exactly on topic, but it's a damn sight closer than a
lot of the garbage I see lately, and I've been a regular on this NG
since the mid-90s.

Thanks!

Grant Erwin
Kirkland, Washington

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Grant Erwin wrote:
Anyone got a clean db meter they don't need and want to sell/trade?

Grant,

There are a bunch of real SPL meters on ebay cheap. You want to make
sure the one you get comes with a microphone, as these were usually plug
ons. You might look for a General Radio or Bruel and Kjaer. Simpson made
them too.

Kevin Gallimore

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Are there any with an external readout? I would like to post one in our
fire hall (we rent it out to pay for being a volunteer fire station.) so
that the patrons who are renting it can see exactly how loud they are.
If a Radio Shack unit can be modified that would be fine, but I an looking
for digits of at least three inches high.
Thanks
"axolotl" wrote in message
...
Grant Erwin wrote:
Anyone got a clean db meter they don't need and want to sell/trade?

Grant,

There are a bunch of real SPL meters on ebay cheap. You want to make sure
the one you get comes with a microphone, as these were usually plug ons.
You might look for a General Radio or Bruel and Kjaer. Simpson made them
too.

Kevin Gallimore

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The Tagge's wrote:
Are there any with an external readout?

I have never seen one with a remote readout. Some have a data output
which presumably could be fed to an external display. Most have an
analog output to drive a chart recorder. The analog output could be fed
to a comparator that could eventually turn on a light at a preset sound
level, warning the partyers.

Kevin Gallimore

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axolotl wrote:
The analog output could be fed
to a comparator that could eventually turn on a light at a preset sound
level, warning the partyers.

Forgive me for answering my own post. A better idea would be to use the
comparator output to kill the power to the amplifiers.

Kevin Gallimore

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