RE: Calibration/Verification of Rotameters

[Glen.Vickers@ucm.com]

I recently purchased a digital mass-flow secondary standard to calibrate the
rotameters at my site.  I wanted to find an alternative to the
bubble-counting flow cell.  If you choose to go with a bubble counter,
ensure your lowest cal point is well above the minimum rated flow for the
cylinder, else the air velocity in the cell will be so slow, that it will
take a significant amount of time to get good cylinder wetting to make
bubbles that can live for a long enough to travel the distance to be
counted.  Kinda like over-carbureting a small block chevy, the air velocity
is too slow to let the carb work properly...

The digital unit is called a Veri-flow 500, has a range of 5-500 cc/min, and
costs approximately $500.  The manufacturer is J&W Scientific and it appears
they use these devices in many high-quality lab environments.  Try
800-552-0413, 800-223-3424, www.jandw.com for more info.

Glen Vickers
glen.vickers@ucm.com



> -----Original Message-----
> From:	William Lorenzen [SMTP:LORENZEN_W@A1.TCH.Harvard.edu]
> Sent:	Saturday, October 07, 2000 11:41 AM
> To:	Multiple recipients of list
> Subject:	Re: Calibration/Verification of Rotameters
> 
>           Is an electronic bubble meter a "primary standard" or a
> secondary 
>           one?
>           
>           Thanks for the clarification.
>           
>           William A. Lorenzen
>           lorenzen_w@a1.tch.harvard.edu
> 
> ************************************************************************
> The RADSAFE Frequently Asked Questions list, archives and subscription
> information can be accessed at http://www.ehs.uiuc.edu/~rad/radsafe.html


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