Measurement of liquid fraction dropout using micropatterned surfaces

A method for detecting a condensate in a gaseous sample, the method comprising:

• receiving the gaseous sample within a chamber defining an enclosed interior volume;
• exposing a patterned structure forming a roughened surface to the gaseous sample, the patterned structure comprising an open volume accessible by the roughened surface, the open volume being at least about 10% of the interior volume of the chamber;
• illuminating the patterned structure;
• detecting at least a portion of the illumination returned from the patterned structure;
• and
• determining from the detected illumination a presence of the condensate on the roughened surface.

An apparatus, comprising:

• means for exposing a patterned structure forming a roughened surface to a gaseous sample, the means for exposing comprising an interior volume and the patterned structure comprising an open volume accessible by the roughened surface, the open volume being at least about 10% of the interior volume;
• means for illuminating the patterned structure;
• means for detecting at least a portion of the illumination returned from the patterned structure;
• and
• means for determining from the detected illumination a presence of the condensate, at least one of reflectivity or scattering cross section of the patterned surface being indicative of condensate on the on the roughened surface.