Method of measuring chromated conversion coating amount using infrared absorbance
AssigneeThe Boeing Company
InventorsPaul H. Shelley, Jacqueline Fritz
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Abstract
A non-destructive method is provided for determining the amount of a chromated conversion coating on a metallic substrate. A value of infrared energy reflected from the metallic substrate without the chromated conversion coating is determined. A value of infrared energy reflected from the metallic substrate with the chromated conversion coating is determined. A value of infrared energy absorbed in the chromated conversion coating is determined, and the value of the infrared energy absorbed in the chromated conversion coating is correlated to an amount of the chromated conversion coating.
Claims22
A non-destructive method of determining an amount of chromated conversion coating on a metallic substrate, the method comprising:
- non-destructively determining a value Ia of infrared energy at a predetermined wavelength within range of 2.5 microns to about 25 microns absorbed in a chromated conversion coating on a metallic substrate;
- and
- correlating the value Ia of the infrared energy absorbed in the chromated conversion coating to an amount of the chromated conversion coating.
A non-destructive method of determining an amount of a chromated conversion coating on metallic substrate, the method comprising:
- transmitting an infrared beam having a predetermined wavelength within a range of 2.5 microns to about 25 microns through a chromated conversion coating on a metallic substrate at a predetermined incident beam angle relative to normal, the transmitted beam having a cross-sectional area to produce a predetermined spot size on a surface of the chromated conversion coating;
- reflecting the infrared beam off the metallic substrate to form a reflected beam;
- detecting the reflected beam;
- comparing infrared energy Ic of the reflected beam with a predetermined value of infrared energy Io reflected off the metallic substrate without the chromated conversion coating to determine absorbance value Ia for the chromated conversion coating;
- and
- correlating the absorbance value Ia for the chromated conversion coating to a chromated conversion coating amount.
A non-destructive method of determining an amount of chromated conversion coating on a metallic substrate, the method comprising:
- transmitting an infrared beam having a predetermined wavelength within a range of about 2.5 microns of about 25 microns through a chromated conversion coating on a metallic substrate at a predetermined incident beam angle in a range from about 70 degrees to about 80 degrees from normal, the transmitted beam having a cross-sectional area to produce a predetermined spot size in a range from about 2 mm to about 35 on a surface of the chromated conversion coating;
- reflecting the infrared beam off the metallic substrate to form a reflected beam;
- detecting the reflected beam;
- comparing infrared energy Ic of the reflected beam with a predetermined value of infrared energy Io reflected off the metallic substrate without the chromated conversion coating to determine an absorbance value Ia for the chromated conversion coating;
- and
- correlating the absorbance value Ia for the chromated conversion coating to a chromated conversion coating amount.
Dependencies are inferred from the claim text.