Measuring Laser Drilled Hole Diameter in Ceramic Specimens

[bhartish]

I have laser drilled hole thin ceramic specimens and I am required to measure the diameter of the holes. Suggest me some methods.

 

[Mike_In_Plano]

Lenox Laser does this kind of work. You may wish to have them perform an analysis using their metrology equipment. Otherwise, some scopes with precision stages will tell you down to about +/- 5 millionths of an inch.

 

[Ranger Mike]

what diameter hole and to what accuracy do you wish to measure?
i have been selling Metrology Instruments since 1980 and can provide some small input to your requirement

 

[jehan60188]

shine a light through it, measure the radius of its shadow, and correct for the distance?

 

[bhartish]

"what diameter hole and to what accuracy do you wish to measure?
i have been selling Metrology Instruments since 1980 and can provide some small input to your requirement"

its approximately 2mm. I am checking for the repeatability of the experiment. But the shape is irregular.

 

[bhartish]

"Lenox Laser does this kind of work. You may wish to have them perform an analysis using their metrology equipment. Otherwise, some scopes with precision stages will tell you down to about +/- 5 millionths of an inch."


Can I get some elaboration on this ?

 

[Ranger Mike]

if the diameter is not round then a diametric measurement is not easy.

there are four most common methods to calculate a diameter.

Maximum Inscribe circle (MIS), Minimum circumscribed circle (MCC), Least Squares method (LS)
and Zone or Minimal Radial Separation (MRS) which uses the MIS and MCC method
to what tolerance do you need to measure?

your desired measurement accuracy will determine the measurement method

 

[bhartish]

I am actually looking into the instruments which I can use.

 

[MRFMengineer]

Any type of decent measuring microscope or optical comparator should work fine, something like these : http://www.mitutoyo.com/TerminalMerchandisingGroup.aspx?group=1410 or http://www.mitutoyo.com/TerminalMerchandisingGroup.aspx?group=1620

 

[bhartish]

Yes fine I am using Tool makers microscope. But I want to know , for an irregular hole , how many measurements would be appreciable?.

 

[MRFMengineer]

The number/type of measurments depends on the specification or function of the hole.

 

[bhartish]

I have laser hole (1mm-2mm dia) drilled specimens . How to measure heat affected zone ?