Cleanliness measurement methods

Everything that shines is not necessarily clean.

If your study is of a biological nature I would define "clean" as "The absences of harmful or undesired bacteria and pollutants".

In that case a non-invasive microscopic count should be done. or samples should be subjected chemical tests.

Enjoy your "big game" watching.

Vaccum the floor over different times and get rate at which dust collects. Then find the dust access points or cause like a door that is opened constantly.

Shine can be shiney dust fibers like abestoes.

I like the idea of your "Glossometer." Perhaps, very pricisely measuring the voltage produced in a photoelectric device at carefully controlled standard angle and range, as a light that produces wavelengths most visible to the human eye is relflected off the floor. In essense, measuring its reflectivity. Naa - that won't work for non-identical surfaces.

A carefully controlled standard swab, and look at what comes off?

The chip fabs have done allot of this work already for both the clean rooms and manufacturing. Contact Intel or IBM etc. If you ask right, you will get more info than you may want.

Do that by explaining what is in it for them. PR, exposure to the students, tax write off, Do a little research and think of something good.

Half of your work will be dealing with others: people; companies; groups with agendas other than your own. Knowledge gained from contacts is key. You could use this to form a networking node. Tag your it.

2bits from Brad

Consider using different colored adhesive backed stickers, the stickers could be scanned for different colors of dirt & chunks of stickers could be cultured for fungus, bacteria. the glue may interfear w/ that last bit. Clean rooms use sticky mats @ the entrance to contain contaminates

First you will have to define what clean is also you will have to define a cleaning method. After that my suggestion would be to start with a controlled set of samples, soil the samples with a known amount of bacteria, dirt, etc. Then use the cleaning agent at different concentrations, this will allow you to decide the minimum concentration needed to clean the surface, but remember you have to define what clean is. You should test all samples in a controlled environment such as a Bio-safety cabinet.

RInse a sqaure foot of the "clean " surface with pure DI water. pour the water through a microfilter . Dry off the water . Measure the weigh of the filter before rinsing and after rinsing . The weight of the filter after is the level of cleanliness of the floor

Use a microscope and all the ideas (including the gloss factor) combining them, then tell your Prof. that such a complex assignment will take much more time to do that allowed. Plus you will require a much larger budget, then over-run the budget.....sorry, I kind of forgot this is a college project....

Randy

The best laugh of the day so far.

Thanks for lightheartedness.

Regards;

Nadeem

09072007

There are several methods that can tell you iff the floor is clean but you must come up with a definition first (as stated before). The most sensitive for organic contaminants is TOC (Total Organic Carbon). This will pick up remnants of any bacteria or molds left behind after the cleaner has done its job. However, if you include a sterile water rinse, after your cleaner has been applied properly, your TOC values should be at the limit of detection of the assay. For non-organic particulates there is equipment available from several companies that can measure airborne (not surface) particles. So if you create an air flow over your cleaned floor this equipment will pick up any particulates from 5 to 0.2 microns in size.

The last post covers pretty much all the bases and I also can not stress enough that you first define what you mean by "clean". You first have to know what you are measuring before you attempt to measure it.

Just to add something extra, there are systems that measure particulates in suspension, so you could indirectly measure surface particles that do not easily become airborne.

Have you looked at various ASTM, etc definitions and test methods for "cleanliness"? National Institute of Standards, Hospital guidelines, etc? Most responses are talking about ways of determining particles, fibers, etc. If the "cleanliness" is that gross, you aren't focusing on "cleanliness". Think biofilm, bacteria, viruses, pollen, tannin leeching from wood, plasticizer from PVC, and a lot of other things.... depending on your definition of "clenliness".

You may also want to check out ASTM. They have a huge data base which addresses all sorts of ways to test anything you can think of.

Chief Illiniwek:

Hi, I'm with Technika and we have a product that might meet your needs.

We have a color analyzer that provides RGB values that can be used to determine the difference between different surfaces. The hand-held analyzer takes color measurements of the tile or concrete and compares the readings of each test with different cleaning solutions. The surface that has the closest color match to the original surface would be considered the cleanest.

Regards,

Richard Burczyk
Marketing Manager
Technika

This may apply for what you are doing. We have used an IR particle counter for tooling cleanliness. We "contained" the test area by blowing clean filtered air onto a surface, capturing the residue and sending that through the IR particle counter.

Most of these people have given you good suggestions.

Like many above, I too say that try and use a combination of them all.

I guess your glossometer idea may not work exclusively since you are using all kinds of floors as your samples. If it is a matte finish floor, you are in a soup.

Anyway, my suggestion is quite simple...... Use some sort of sticky tape. (It goes with the idea of distilled water only ot is less messy). You can pick the adhesive besed on the tests that are to follow. This allows you to log the contaminants too. Thus, a toxicology lab can be messy but is dangerously "unclean" if any toxic wastes are found. Your machine will be able to detect and rate things accordingly. The same for hospitals etc.

Gloss etc can be optional functions which may be checked seperately.

This cello-tape like thing... can be looked at under microscopes, spectroscops etc... and maybe analyzed hence

Hi again,

Thank you for some great comments and suggestions for our project. As some of you have noticed its kind of difficult to assign a level of cleanliness to a floor. It looks like we are going to have to rule out particle measurements in the air above the floor surface. We just don't have the necessary equipment and for the size of area we will be cleaning it doesn't seem feasible. We are have the following ideas: RGB scanner (thanks Technika), tape test, surface materials density and/or weight, Q-tip swab, Black light inspection, and glossometer. '

Thanks again,

Chief Illiniwek