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Date: Tue, 1 Mar 2005 08:23:10 -0700
From: Bob White <bob@bob-white.com>
To: "Rotary motors in aircraft" <flyrotary@lancaironline.net>
Subject: Re: [FlyRotary] Re: flow measurements
Message-Id: <20050301082310.2e230c8a.bob@bob-white.com>
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Hi Todd,

This guage uses a pressure differential thru an orifice.  

See here:  http://www.nciweb.net/liquids.htm

My guage is for a 1 1/2 inch pipe and the orifice is around 3/4 inch or
so.  That may introduce some restriction, but I'm hoping it isn't
enough to change the readings too much.  This could be used in flight
if I ignore the requirement to not change the pipe diameter for a
length of 10 diameters.  The guage includes a transmitter so that I
could get readings remotely. 

I will have to take a look at the guage Rusty found.  I just couldn't
find anything retail at a reasonable price.  Since I don't quite have
the engine running yet, I'm going to try getting a little temperature
data by blowing a hot air gun on the radiator.  I've decided to stick
with 50/50 ethylene glycol for my initial tests.  I'm glad the scale
problem was mentioned as I will now use distilled water from the start.

Bob White


On Mon, 28 Feb 2005 22:50:29 -0800
"Todd Bartrim" <haywire@telus.net> wrote:

> Message
>    I bought an RCM-7000 guage on ebay for $50.00 with a measurement range of
> 4 to 30 GPM.
> 
>   A Google search for RCM-7000 only found a "coverslipping machine" whatever
> that is? So what sort of flow gauge is it that you've got there?
> 
> 
>    I ended up buying two mechanical gauges from McMaster Carr.  One is 1-4.5
> gpm, and the other is 5-30 gpm (the highest in that type of gauge).  Each
> was $59.
>    Rusty
>     Same Question? Whacha got? Can either of these be used in flight or is
> it just for ground tests? Are these an orifice type? (square root extraction
> of DP). If so then they will add a little restriction, but this is where
> that pressure recovery and permanent pressure loss comes into play.
> 
>   The best, most accurate and least restrictive way to measure is using a
> magnetic flowtube, which I used in my initial testing. Unfortunately these
> are unsuitable for in-flight use due to weight, size, $$$$$$$$$$$, and power
> requirements.
> 
>   The Signet flowmeter that I used was $543 CAD. At least that's what my
> uuhh... "supplier" had paid for it. (obsolete stock)
> 
>   Todd Bartrim
> 


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