Spectrophotometer for the automated optical characterization of solar collector tubes and method for the operation thereof

A spectrophotometer for automated optical characterization of solar collector tubes, the solar collector tubes being formed by an inner metal tube and an outer glass tube, wherein the spectrophotometer is placed on a measuring bench, and wherein the solar collector tube to be characterized is placed in the measuring bench, the spectrophotometer comprising:

• a light source that generates light for measurement of a coefficient of transmission of the outer glass tube and a coefficient of reflection of the inner metal tube of the solar collector tube in the measuring bench;
• a measuring module comprising two or more lenses and first and second light detectors, the measuring module receiving light from the light source and the two or more lenses positioned such that a first portion of the received light is directed through the outer glass tube to the first light detector and a second portion of the received light is simultaneously directed to the surface of the inner metal tube and to the second light detector after reflecting from the surface of the inner metal tube, the first and second light detectors producing respective signals indicating the intensity of light falling on the light detectors;
• a mechanical system of linear displacement that displaces the measuring module in an automated manner along the length of the solar collector tube, the spectrophotometer measuring the coefficient of reflection of the inner metal tube and the coefficient of transmission of the outer glass tube at multiple points along the length of the solar collector tube;
• an electronic system of data acquisition and processing with an analog/digital converter, the electronic system of data acquisition receiving the output signals from the first and second light detectors;
• a computer for controlling the spectrophotometer and processing the measured data;
• and
• a system of communication between the electronic system of data acquisition and the computer.