Color measurement

A method for measuring a parameter of a liquid coating, the method comprising:

• providing a mechanical carriage connected to a surface configured to receive a layer of the liquid coating, wherein the mechanical carriage is configured to move from a retracted configuration to an operative configuration located at a set distance and orientation with respect to the surface;
• locating an optical device in the mechanical carriage when in the retracted configuration;
• moving the mechanical carriage to the operative configuration;
• while in the operative configuration, adjusting an orientation of the optical device within the mechanical carriage to an aligned orientation based on a relationship between the surface and a mechanical alignment feature on the optical device;
• after adjusting the orientation of the optical device within the mechanical carriage to the aligned orientation, retracting the mechanical carriage from the operative configuration to the retracted configuration and removing the mechanical alignment feature from the optical device;
• and
• returning the mechanical carriage to the operative configuration before performing a parameter measurement operation with the optical device in the aligned orientation.