Klarinet Archive - Posting 000733.txt from 1998/12

From: "Diane Karius, Ph.D." <dikarius@-----.edu>
Subj: Re: [kl] Gas flow rate in clarinet
Date: Sun, 20 Dec 1998 03:20:59 -0500

Warning: Science spoken below.
> 1) Does anyone know the value(s) for "normal" flow rates, or where this
> information might be found in the literature, or how the measurements were
> made. (Sticking a cork in the bell with a tube to a flow meter seems
> unlikely; I would think it would seriously affect the intonation, resistance
> and everything else.)

I've not been able to find information on this (I'm interested from
the stand point of conducting research on voluntary control of
airflow in humans (and muscians :-)). Right now I'm working on
modifying the barrel of a throw-away clarinet to see if I can turn it
into a flow transducer (linear resistance connected to a pressure
transducer) and still maintian some semblance of playability. If
you want, I'll let you know what I come up with.

>
> 2) Does anyone know of measurements of carbon dioxide concentrations in the
> bore of a clarinet (or other instrument) during use? If so, where are they
> published?
I haven't been able to figure out how to measure this (and I have an
end-tidal CO2 monitor), but it should be standard exhaled air
(average Pco2 in the vicinity of 30 - 40 mm Hg). I know that the
normal "average" exhaled PCO2 is usually listed in the vicinity of 40
mm Hg, but in all honesty I have never measured an exhaled CO2 value
from an _awake_ individual that was that high (usually around 35 mm
Hg). Actually, now that I've written this, I've come up with a
different way to approach this (have no idea if it will work - I'll
have to play with it).

>
> 3) Does anyone know of any published work on gas-replacement (nitrogen,
> argon, etc.) with wind instruments?

Can't help you there.
Diane R. Karius, Ph.D.
Department of Physiology
University of Health Sciences
1750 Independence Ave.
Kansas City, MO 641o6-1453
email: dikarius@-----.EDU

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