Federal 2001-130 ANSI testing ???????

[Jpressman8]

I hope that will get the ball rolling. 8)

[Hacksaw]

BRRC was involved in some siren system testing:

http://www.blueridgeresearch.com/090043.htm

http://www.blueridgeresearch.com/070015

As I remember, there was a big fuss about ATI problems at Indian Point.

[SIRENMAN]

Thanks Hacksaw I spoke to this company as I previously posted and they have not tested the 2001-130 or the 2001SRNB. Thanks again and keep looking

[SIRENMAN]

Acoustics 101 wrote on another post on this site:

I just read the report. Federal tests their sirens in an anechoic test chamber. The problem with using only this method is that it doesn't account for atmospheric absorption loss, which is at the heart of why two systems of equal dB rating at 100 feet may measure totally different from a distance of a mile or more. The farther you go from each source, the greater the disparity.

They then go on to estimate a loss of 10 dB per doubling the distance. That's not the way things work in the real world. In addition to the inverse square law loss of 6 dB/doubling the distance, there is a frequency dependent loss of x dB/1000 feet which increases with frequency. From a distance of 10,000 feet a pure 1 kHz tone will be about 12 dB softer than a pure 400 Hz tone. If one tone is of a different tonal spectrum (harmonic content) than the other, the tone with higher harmonic content will fall off that much faster with distance than the above prediction.

A high frequency tone of high harmonic content would be the worst case, as the higher frequencies in the harmonics would contribute only to the nearfield annoyance factor, not farfield propagation and penetration of structures.

Just think of an ATI and a Whelen of equal dB rating at 100 feet. Which of these would be better heard from inside your home from 1 mile? The answer is obvious, as high frequencies have higher atmospheric losses in dB/1000 feet. It really doesn'y make much sense to only measure a unit's performance in an anechoic chamber or the near field, as it is the far field performance that really counts.

[acoustics101]

Testing in an anechoic chamber will give accurate results as far as extrapolating the distance to the first 100 feet where atmospheric absorption of higher frequencies is not a problem. The problem is trying to predict how the unit will perform at distances of several thousand feet, where frequency dependent atmospheric absorption loss becomes a major part of the equation. These are the distances at which the device needs to be effective for warning the public-not to deafen them at 100 feet.

At these greater distances it is no longer the simple inverse square law loss of -6 dB/doubling the distance and most assuredly not the totally arbitrary loss of -10 dB/doubling the distance often quoted in siren literature.

A pure tone of 500 Hz will have an additional loss of about 1 dB/1000 feet while a pure tone of 1 kHz will lose about 2 additional dB/1000 feet in addition to the inverse square law loss. If the frequency spectrum includes harmonics, the loss is even greater, due to the higher frequencies present in the harmonics. The 70 dB radius of a device is much more important than what the it can do at 100 feet on axis. If this 70 dB radius is based on actual tests rather than estimates you will find that this radius increases dramatically as the frequency decreases if based on devices of equal dB rating at 100 feet.

The secret to an effective warning device is to provide high output at frequencies low enough to propagate far and penetrate structures well while being high enough to be easily audible on the Fletcher-Munson curves of equal hearing at SPLs of around 70 dB. These optimal frequencies are about an octave below what many sirens currently use.

In 2009 I bid on the siren upgrade in Hamilton County Ohio and part of those bids were to supply independent testing data for your siren according to ANSI standards. ANSI Standards S12.14 lays out the standards of testing, which is to measure 100' from a siren and record the sound. Federal does their testing in their chamber at 10' away and calculate the sound output. I turned in the independent test for the T-128 and Federal turned in a test for the 2001SRNB dated in November 2002. The bid was thrown out for a reason not beknown to me, but it was rebid and low and behold the testing requirement was not included in the bids this time.

Therefore I have concluded that Federal never tested their 2001-130 and just said it put out the 130db. just for the hell of it and to keep up with ASC. I can find no testing data or anything to prove me wrong. If any of you know one way or another please let me know.

Here is their test:

[SIRENMAN]

It is a simple fix let's put a T-128 and a Federal 2001-130 next to each other and test them side by side. Then send the data to all EMA directors in the country and publish the results in the trade magazines.

In a letter from Hamilton County EMA they recognize the fact that the 2001-130 does not have the range as the T-128.

[acoustics101]

Great idea! I'm surprised no one has mentioned it before. Simply test two units of equal dB rating at 100 feet side by side and compare the 70 dB radius of each. It is the 70 dB radius that really matters. Far field performance counts for much more than near field, as that is what has to reach the public.

We also need to toss out that ubiquitous 10 dB/doubling the distance estimate. It is simply inaccurate and tends to put all devices of the same dB rating at 100 feet on an equal ground with each other when obviously they are not. It also tends to give pessimistic results within the first few hundred feet and overly optimistic results in the thousands of feet that follow.

We need to be using information based on the inverse square law and frequency dependent atmospheric absorption loss instead of arbitrary estimates. These arbitrary estimates are the monkey wrench that has remained in the works now for decades. It has enabled companies like ATI to successfully compete in the market for being able to achieve similar nearfield performance. We need to stop thinking nearfield and start thinking farfield. Getting rid of this crutch for good will free us to honestly rate warning systems as to their actual effectiveness.

A number of years ago I suggested that warning devices be rated in terms of square miles/HP or square miles/kW, based on a 70 dB radius. This would be a much more useful and telling rating than simply dB at 100 feet. It would separate the men from the boys and the tools from the toys.

It is a simple fix let's put a T-128 and a Federal 2001-130 next to each other and test them side by side. Then send the data to all EMA directors in the country and publish the results in the trade magazines.

In a letter from Hamilton County EMA they recognize the fact that the 2001-130 does not have the range as the T-128.

[SIRENMAN]

Acoustics 101 writes the following:

All high power warning devices are not created equal. A simple dB rating at 100 feet doesn't tell the whole story. Sound doesn't decay by 10 dB per doubling the distance or any other arbitrary rule. Propagation loss depends on the inverse square law of -6dB per doubling the distance plus a frequency dependent atmospheric absorption loss of x dB per 1000 feet. Factors to consider are the fundamental frequency, the frequency spectrum and the directivity index.

A very loud warning device of high pitch does little more than irritate those within the first 1000 feet of it. Just think about an ATI siren. A lower pitched device of equal dB rating at 100 feet will decay far less with distance and penetrate structures and vehicles that the device of higher pitch will never reach. It also sounds less irritating to nearby ears.

[Jpressman8]

Look at this garbage. This is the same system that malfunctioned here about 2 weeks ago. Looks like they have made their decision. Here's the link to the Ad on Federals site. What a bummer I think we are screwed. David Pepper Quote: I think this will literally save lives :UnQuote. Thank you Todd Portune, David Pepper, EMA and Company. The 2001 siren virus is about ready to hit Hamilton County. . UHHGGG!!!! I'll be sending a letter to the Mayor.

http://www.federalwarningsystems.com/

A failure waiting to happen.

https://hamco-oh.smartmsg.com/

[SIRENMAN]

This is the same system that had an epic failure in Hamilton County a few weeks ago. I hope this teaches Hamilton County EMA what to expect if they decide to go with the 2001-130 the untested 130 db siren that has never been tested according to ANSI standards.