How much boost?

[red04stanggt]

Dumb question...but I registerd a long time ago but have always been curious about the sirens. It seems to me like whenever the real deal is happening the sirens seem louder but maybe its b/c im outside my house with the camera looking for a twister. Even then I remember back in the day even in my house it was still loud. Is there a difference between tests and when they need to be used? It seems as when they are testing them I dunno just doesnt seem loud. I think they are ran by roots type blowers arent they? If so how much PSI is going through those things?

[pyramid head]

So it sounds like you are near a Thunderbolt or Hurricane. I guess they could keep the blower off for testing seems how older controls had switches for what was to be on. The PSI that is ran through a Thunderbolt was I believe 6 or 6.5? Someone do correct me if I am wrong.

[AllSafe]

Five or six PSI but the blower moves huge amounts of air at that pressure- probably 700-800 cfm.

[red04stanggt]

So it sounds like you are near a Thunderbolt or Hurricane. I guess they could keep the blower off for testing seems how older controls had switches for what was to be on. The PSI that is ran through a Thunderbolt was I believe 6 or 6.5? Someone do correct me if I am wrong.

Whatever siren it is its by my house and the actual horn looks like the one at the top of this page on the left. Who actually controls them in a big city and how? Is there a main board or somthing somewhere? Either way they are controling somthing b/c its not NEARLY as loud when its testing

[Robert Gift]

Tests in Denver are just like real at full power but of shorter duration than an actual warning.
Don't know how one could accomplish anything but full power on three-phase.

But would be nice to test a Thunderbolt without the roots blower operating.
But the blower is probably the stage most prone to failing so I'd want to test it also.

For visitors at times other than the published Saturday noon test, I have done growl tests on the 2t22 by turning the switch on and quickly off.
I had to be fast or it got too loud too quickly!

[OrnAlert]

Whatever siren it is its by my house and the actual horn looks like the one at the top of this page on the left.

Yes, that's a thunderbolt, and it is alot softer when the blower is off, according to some videos where the blower cuts out and the siren volume decreases rapidly.

[Jim_Ferer]

A Thunderbolt uses a Roots-type blower to move air through the chopper, so that the throughput of air does not depend on the action of the vanes in the chopper. I believe that a Thunderbolt's blower moved about 250 cfm at 6.5 psi (I'm not positive about the pressure - 6.5 pwi may have been the point where the relief valve opened).