Part Dryness Measurement

[AllanSG]

Hi Guy,

I got a question. How do i measure dryness on part.

I have process that require to water wash and blow dry a adsorber shaft. Is there a way to measure how dry the shaft is after blow drying?

Appreciate all help here.

Allan

 

[patprimmer]

Weigh it maybe?

Regards
Pat
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[140Airpower]

Alan, how dry does it have to be? Why isn't visible dryness enough? Note that most surfaces at room temp will have some water unless you keep it in a dessicated environment.

 

[AllanSG]

Hi guys,

I have thought of using weight but this is stainless steel shaft that weigh around 1 to 2 pounds. The weight of water on the shaft will be insignificant to measure.

My customer suggested a contamination target to be <0.7ppm. I have no idea how i can measure this.

Is there any method to measure the dryness. In the harddisk industry, they uses Karl Fischer. I am not sure if this is good for this application. it seem like overkill
to me. Is there any process in the automobile industry that really measure part dryness before assembly?

My customer is not in favour of visual dryness.

Allan.

 

[140Airpower]

Allan, in a humid atmosphere, all surfaces that are not hydrophobic have water molecules. They are not "wet" per se, but they are not dessicated. To achieve greater dryness you would need to heat the part to above 212 degrees and transfer it hot to a dessicated environment, a chamber of some sort that is sealed and contains a dessicant, normally a salt that absorbs water tenaciously, like Calcium Chloride. This kind of treatment is extravagant, IMHO. Otherwise, just heat the part to about 160 degrees and let it cool. It will soon become like every other surface in an atmosphere that contains water vapor. See if your customer will accept that.
What's the purpose anyway? Is it to prep for coating?

 

[AllanSG]

Hi 140 Airpower,

Thanks for the advise, i will check with the customer on this. This process could be too length and they might not accept it.

This is the shaft of the car absorber. They dun wan any water to go inside the chamber which cause corrision.

Allan