Designing a relevant, accurate vacuum test

[wyaple]

I’ve been thinking of the best way to create the most revealing test(s) and show the most accurate results when deciding who "wins." One area of testing that has really bugged me is the ridiculous number of complete passes some testers and many (most?) laboratories perform. Let’s begin with simple Mathematics.

Suppose that:

Machine A has 120 CFM and we know that it can pick up 50% of the test dirt in one complete pass.

Machine B has 90 CFM and we know that it can pick up 33% of the test dirt in one complete pass.

Machine C has 60 CFM and we know that it can pick up 20% of the test dirt in one complete pass.

Test #1 is now run and includes 5 complete passes.

Result for machine A: After picking up all it can in the first two passes, the remaining three passes are essentially useless.

Result for machine B: After picking up all it can in the first three passes, the remaining two passes are essentially useless.

Result for machine B: After five passes, essentially all the dirt is picked up.

Conclusions: Mathematically speaking, a one pass test would show the most difference between the three machines while a five pass test would incorrectly show nearly no difference. Since most people only vacuum in one complete pass anyway, shouldn’t we be concentrating more on one pass tests? And that test should be performed at medium speed, not turtle speed, right?


Bill

 

[real1shep]

Totally agree.....

but I think where you're gonna get some argument is in the media itself to throw on the floor. I think it should resemble the dirt we face every day. And maybe that shouldn't be walnut shells, red sand or sawdust etc.

I don't have an answer, but I think demo salesmen for yrs have taken advantage of certain media that may not be relevant to real-world everyday household dirt. Media that they knew their particular machine would shine with.

Kevin

 

[sebo4me]

That's a good point Bill.

I think a test should be as close as possible to how an average person would use a cleaner and use collected dust from a used bag.