PAC's Alcor VTR-100 (Visual Tube Rater) is used to manually rate heater tube deposits formed during a jet fuel thermal oxidation test. Manual visual rating is the only approved heater tube deposit rating techniques allowed in ASTM D3241 and IP323.
The heater tube is attached to a holder and inserted in the VTR-100, along with the ASTM Color Standard (included). The tube holder may be moved up and down and rotated to locate the darkest section of the tube; the color codes on the ASTM Color Standard may be moved adjacent to the section of the tube being rated. Both are illuminated by special lights and are easily observed through an attached viewer.