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Perception of Gauges

>> Why are so many people so anti gauge? <<

I can tell you one reason is the cost of a lot of the high-end vacuum type vs.
spark coil "perception" techniques. For the most part I simply know that if I
can see ANY plasma activity within the manifold via spark coil, that is not
acceptable vacuum. For neon work I don't see the need for any more resolution
than that. Not that I'm not a gauge kinda guy. As you know, I do audio and
without my gauges, I'd be lost. As for milli-amp meters for bombing, we find
that the wood blocks (our version of a choke or milli-amp control) work fine. We
tuned them to the pump speed and electrode shells and while there are some tube
differences (lots of impurities, phosphor differences, etc.) the time and
temperature for the tube heat and trode heat cycle works out very well. So I
guess you can say that those blocks are a sort of gauge. At least they are a
constant in a variable system.

>>  But your preceptions change all the time <<

Morgan is right about this one and this a case where gauges do come in handy.
Sometimes the gauges will tell you something that your perception says just the
opposite. Here is where he says it is hard to figure out what is really going
on. But without the gauge, you would never have suspected the disparity. I'll
give you an example from last night's show. Bobby Vinton brings his own sound
guy so all I had to do was play a music piece on a DAT tape and also play an
announcement to get the opening act comic onstage. I faded the house music, hit
the DAT tape and got ready to play the announcement. Only I didn't hear the DAT
music! I looked over at the deck and the meter (gauge) said it was playing but
my perceptions told me that it was not getting through to the PA. So I stopped
the tape, checked the sound board for what might be the problem and after
deciding that it should be working gave it a second go. This time I pushed the
volume up even higher than the normal factor for the noisy crowd. I barely heard
the music so I pushed it up even higher and proceeded with the announce. The
comic came on and the rest was history. Later on I was talking to the person on
stage and he mentioned something that I forgot all about. The sound system
speakers are BEHIND the act curtain. During the rehearsal the curtain is always
open so when I played the DAT and the announce earlier in the day they were
plenty loud but the curtain doesn't go up until the announcement is part way
through for the real show. No wonder I couldn't hear it. But the point of all of
this was that you have to use both perception AND some sort of reality check
(like a meter or gauge) to have that consistency Morgan was talking about. If I
simply believed my senses, then the tape MUST NOT be working! If I believed the
tape meters, then it must be playing and there is another explanation for my
senses failing me. A combination of the two got me through. I find that it is a
big mistake to assume anything.

>> Oh yeah, for those who have not heard of it, Templaq is a "paint" 
that you put on your tube. A small dab near the center. It dries
in a minute or two. <<

This is made by the same people who make the crayons (also called Tempilstiks).
They make surface temperature indicating products that melt (and go from opaque
to clear) at a specific temperature. I use them for annealing pyrex, bombarding,
warning indicators so I don't melt tight sections of neon sculptures, etc. They
make around 120 or so different temperature indicators from 100F. to 2500F. in
around 50F. increments with an accuracy of +/- 1% of the temperature being
measured. I prefer the paint for reasons already stated. a 2 oz. bottle sells
for around $6 so we have to order other stuff to get up to the $25 minimum from
our scientific supply house. It is thinned with Carbo-chlor (dry cleaning fluid)
and will last a very long time if you just add thinner every once in a while.

>>  I have heard "newspaper only" many times. <<

As Morgan stated, I doubt that the accuracy is anywhere near +/- 1% of the
intended measurement. This is a very subjective way of measurement and since
Morgan is an Engineer, he is/was taught to avoid such things where repeatability
is of concern.


  E-mail from: Tom Biebel, 17-Feb-1996

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