Re: Zefon bio-pump plus vs. Buck bioaire

[Guest guest]

The Zefon instruction manual states the following:

1. " A Flow Indicator is supplied with the pump for easy calibration.

Bio-Pump may also be calibrated using the optional Air-O-Cell Bubble Tube

for precise calibration. " DO NOT calibrate Bio-Pump with any other device.

The impeller fan-type motor is very sensitive to pressure changes and must

be calibrated using customized low resistance methods. "

2. " About the Flow Indicator - The flow indicator supplied with the Bio-Pump

has been specially designed and calibrated to show an airflow rate of

15L/min. This flow indicator has been designed to simulate the natural

back-pressure of the Air-O-Cell cassette, therefore it simulates in-line

calibration. DO NOT attempt to verify calibration of the flow indicator with

any device other than the Air-O-Cell Bubble tube. Attempting to calibrate

the Bio-Pump or the flow indicator with any other device will show an

incorrect flow rate. "

Taking into account the above, I remain befuddled on how to achieve a

primary calibration using a Bios Dry-Cal on either the Zefon pump or the

rotometer. If I'm reading Zefon's instructions correctly (and I have

discussed this at length with the Zefon rep) here's my problem:

- You can't directly calibrate the Zefon pump directly with Dry-Cal because

of it's sensitivity to back pressure.

- And since the Zefon rotometer is designed to work only " in-line " with the

Zefon pump, if you calibrate the Zefon rotometer using another pump the flow

will be off when you use it to check the Zefon pump.

So how the heck does one get around these limitations?

I really like the Zefon system for the reasons most have stated, and I have

no problem with using the primary calibration of the rotometer as my gauge,

but I can't seem to grasp how y'all rationalize that the calibration methods

you suggest are acceptable.

BTW, I understand that the ever changing spore distribution creates a much

larger margin of error and that I could achieve what I want with added time

and effort (i.e., bubble tube and a stopwatch) ... I'd just like to

eliminate as much error as feasible, in this case flow rate, with the least

amount of effort and expense.

Please be detailed in your response if possible, as I am rather slow:).

Re: Zefon bio-pump plus vs. Buck bioaire

>

> Rob:

>

> I have several Zefon units. They have worked and worked fine without nary

a

> problem, they are easy to use, I can sample all day (40 to 50 samples) and

> the battery seems to hold up real well, and the case is great for carrying

> the unit and about 10 AOC cassettes. The Buck Bioarire looks great too, I

> just have not had the opportunity to use one; therefore, no negative

> implication there.

>

> For what it is worth....

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[Guest guest]

Group,

I believe the statements given below are right on the mark… it is minutia, but unfortunately you may have a difficult time convincing a jury of that fact.

I was collecting air samples in a case that involved millions of dollars in damages. I was very concerned that I did everything by the book when I collected the samples. I wanted to make sure I could defend my data if I were called to the stand.

In industrial hygiene, the rule of thumb is that you calibrate your rotometer at least yearly. I know some people that do it every six months. I bought the optional Air-O-Cell Bubble Tube and after a year of use I calibrated the rotometer against this primary standard. I found that when the ball in the rotometer was right in the center of the 15 l/min. line, the actual flow rate was a little higher that 17 l/min. I then lowered the flow rate until it was 15 l/min and drew a new line on the rotometer representing this flow rate.

I found that calibrating the rotometer with a bubble tube is very cumbersome, so I recently purchased the mini-BUCK™ Calibrator recommended by Zefon. I now feel confident that if I’m involved with a similar case, I will fell a lot more relaxed.

My two cents.

, MS, CIH, CIEC

Re: Zefon bio-pump plus vs. Buck bioaire> > Rob:> > I have several Zefon units. They have worked and worked fine without narya> problem, they are easy to use, I can sample all day (40 to 50 samples) and> the battery seems to hold up real well, and the case is great for carrying> the unit and about 10 AOC cassettes. The Buck Bioarire looks great too, I> just have not had the opportunity to use one; therefore, no negative> implication there.> > For what it is worth....This E-mail scanned for spam and viruses by ATG Internet.FAIR USE NOTICE:This site contains copyrighted material the use of which has not always beenspecifically authorized by the copyright owner. We are making such materialavailable in our efforts to advance understanding of environmental,political, human rights, economic, democracy, scientific, and social justiceissues, etc. We believe this constitutes a 'fair use' of any suchcopyrighted material as provided for in section 107 of the US Copyright Law.In accordance with Title 17 U.S.C. Section 107, the material on this site isdistributed without profit to those who have expressed a prior interest inreceiving the included information for research and educational purposes.For more information go to: http://www.law.cornell.edu/uscode/17/107.shtml.If you wish to use copyrighted material from this site for purposes of yourown that go beyond 'fair use', you must obtain permission from the copyrightowner.