Contact angle standard for proof of reproducibility and accuracy of contact angle meters

 

 

Contact Angle Standard description and application

 

The contact angle standard is a glass plate with images, representing sessile drops with different contact angles.

The contact angle standard is manufactured by a high accurate lithographic process, so the images itself are very accurate according the given CAD-data. The Glass plate is placed on the measuring table instead of a real drop.

The proof of the reproducibility of the contact angle measurement is performed by a repeated measurement of the object (sessile drop). For a correct test, the measurement must be performed, using the live video (not a frozen image). For a real sessile drop exists the problem, that it evaporates permanently. The result of the permanent evaporation is the permanent change of the contact angle. Therefore, the proof of the reproducibility of the contact angle measurement is not possible, using a real liquid, since the object changes permanently the contact angle!

 

The contact angle standard does not change the form (contact angle) and can be used therefore as object to proof the reproducibility of the measuring system.

Moreover, the pictures are manufactured very accurate and symbolize different contact angles. Therefore the contact angle standard can be used perfectly to proof the absolute measuring accuracy of a contact angle measuring system!