terminology?

[hup_d_dup]

That meaning is clear to you, because you're acquainted with the context it comes from (internal combustion engine diagnostics.) Not everyone has that background.

Correct. The word as used is parlance. Not everyone knows everything. An outsider coming in has to learn.

Hopefully the person who is learning comes with enough education to already know the commonly used definition of compression (it doesn't have to be at the level of engine diagnostics), and enough common sense to understand that this is a novel use of the word as it relates to valve leakage.

Parlance is not necessarily inaccurate. Parlance may actually be more acurate when it has a precisely understood meaning among a select group of people.

Hup

[PaulMaybery]

Ah! Me thinks me might be on to something here. The test, to which I believe we are referring, usually is commonly termed a "compression test." This involves pumping air into the void under pressure (compression) and measuring how long it takes before it leaks out. So, the purpose of the test is to ascertain the degree of leakage. Unlike a combustion engine, we do not depend on the level of compression to be of assistance in driving the piston with a greater degree of power. The degree of leakage on tuba pistons contributes to the quality of the sound passing through. It would be interesting if we could produce accentuated notes by simply banging the pistons down harder. But it doesn't work that way. In that light, compression is referring to the test itself which employs compression as a means to arrive at a measurement. PHWEW!!!

On a side note - and humorously intended - I have often wondered what it might be like to have the Tubenet "talking heads" or if you prefer the TNFJ all in one room at the same time and able to contribute almost instantaneously to inquiries. I find these posts both extremely entertaining and for the most part, pretty darn informative, or at the very least thought provoking. The term "tuba intelligencia" might be an oxymoron, but this humble site certainly entertains some rather deep thinking folks who enjoy sharing their knowledge and wisdom. I love it.

Mabes

[Donn]

On a side note - and humorously intended - I have often wondered what it might be like to have the Tubenet "talking heads" or if you prefer the TNFJ all in one room at the same time and able to contribute almost instantaneously to inquiries.

Well, of course each of them is able to reach out with their Internet tentacles and do just that. The problem is that some also have jobs or are otherwise occupied part of the time, so are unable to attend to Tubenet freak jury duties promptly. What we need is funding to maintain a dedicated paid TNFJ staff.

[PaulMaybery]

I could be for investigating forming a DENSA chapter. On the other hand, that might just ruin our little paradigm if we some how manage to legitimize things. Perhaps it might be best if we just all continue to sit at our computers all day in our PJs and Bunny Slippers, vacillating back and forth from Facebook to Tubenet, and occasionally just pissing off someone. Speaking for myself, I've grow quite good at it: Getting folks POed that is.

[Donn]

I have to see the contract first.