When it comes to evaluating particle residues remaining on parts after manufacturing, the “go to” is often particle counting.  Particles remaining on parts after normal manufacturing operations are collected using a secondary, more aggressive washing method.  Collected particles are then tallied by size, number and, in some cases, type and probable origin as a measure …

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In a very early blog written in 2011 I talked about the “Scotch” tape test for cleanliness.  At that time I did not address quantification of the results other than as a visual assessment.  In addition to evaluating general cleanliness, this technique is being found particularly applicable when determining the cleanliness of substrates that “shed” …

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As I was writing the recent post about gravimetric Millipore testing it occurred to me that I was trying to boil a good-sized part of a 180+ page document into 500 or so words.  It also occurred to me that many people don’t have the time for or interest in reading endless pages of specifications …

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Millipore testing is all about evaluating cleanliness based on the presence of particles or other solid, non-soluble contaminants.  In general, it can not be used to detect the presence of hydrocarbons or other contaminants which will be solubilized in the extraction process.  The results of Millipore testing are generally expressed by weight using gravimetric analysis …

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“Millipore” testing evaluates cleanliness by extracting particulate contamination from a surface and then either weighing or counting and quantifying the collected particles to assess the cleanliness achieved by a prior cleaning means.  The first step in either case is to collect and prepare for analysis any particulate residue remaining on the surface after pervious cleaning.  …

The post Millipore Specifications Update – Extraction and Sample Preparation appeared first on CTG Technical Blog.

Once in a while a question comes up that I can’t think my way through.  Here is one.  Within an insulated system there is air passing over a heat source that constantly produces a certain number of BTU’s per hour.  In the process, the air is heated from the inlet temperature to an elevated temperature …

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Thank you to all of you who responded to my plea for insight regarding Millipore testing using particle counting methodology.  Your input has given me some direction and insight into your experiences with this method.  Anyone else who would like to chime in is more than welcome.  Respond in the comments section below or email …

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It would make sense that variations in the aluminum foil used for testing in the foil test for ultrasonic performance could have a bearing on the outcome of the test.  Most people use standard “grocery store” aluminum foil for testing because it is inexpensive and widely available.  So let’s talk about that first.  The most …

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I just spent a couple of hours re-reading several of the ISO specifications related to “Millipore” testing including ISO16232-3 and -7.   I put the word Millipore in quotes here because although these are normally called Millipore specifications, none of them mentions the word Millipore.  (Millipore happens to be the name of a company that developed …

The post Millipore Testing – Help! appeared first on CTG Technical Blog.

After three + months of sheltering in place, things are slowly returning to the “new normal” here in New York state which is where I write this blog.  We all know all too well what’s been going on around the world over the past several months so I’m not going to belabor those details here.  …

The post Welcome Back! appeared first on CTG Technical Blog.

Task At Hand – In a previous blog I declared that I am not a fan of the aluminum foil test for evaluating ultrasonic performance.  I question its validity and relevance on a number of fronts.  If my purpose here is to question my own skepticism, then I guess I should probably define the factors …

The post Aluminum Foil Test for Ultrasonic Performance – Potential Problems appeared first on CTG Technical Blog.

Until recently, I was only able to theorize about the mechanism involved in the perforation of aluminum foil by ultrasonic cavitation.  I no longer have to theorize! My theory had always been that perforation of aluminum foil was due to the repeated flexing of aluminum foil as cavitation implosions occurring on opposite sides of the foil …

The post Aluminum Foil Test – Foil Perforation Mechanism appeared first on CTG Technical Blog.

If you’ve heard of ultrasonic cleaning you’ve probably heard of the aluminum foil test.  The practice of putting a piece of aluminum foil into an ultrasonically activated tank of water probably began as a novelty demonstration.  The holes produced in the aluminum foil by the collapse of cavitation bubbles at least showed that something interesting …

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It was in 1962 during my junior year in high school when my chemistry teacher, Mr. McBain, described an unusual phenomenon related to a specific element.  At the time, I think it was more intended as a test question to see who had studied their notes.     I recently witnessed this phenomenon for the first …

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Liquid level sensors are used to indicate liquid level by sensing the presence of a liquid using several different means. The “float” type sensor is the one that probably comes to mind first for most of us.  The float valve in a toilet tank is a prime example. In the case of the toilet, a …

The post Liquid Level Sensors – Floats appeared first on CTG Technical Blog.

Drying is the last and often a critical part of a cleaning process.  In many cases it is also the most time and energy consuming.  It is often the most difficult part of the process to specify and control.  Although there are several drying technologies available, blowing with hot air is simple and by far …

The post Hot Air Drying – Tips and Pitfalls appeared first on CTG Technical Blog.

Using the right amount of chemistry is important to successful industrial cleaning.  Since there is no standard convention for expressing the amount of chemistry to use, it sometimes takes a little effort to sort things out.  Chemistry is supplied in either liquid or powder form with several different conventions for each.  Let’s look at liquids …

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