Abstract: A rail system made of one or more flexible guide rods, each consisting of a tension rod, is used to support lightweight, mobile devices such as carriages, scanning heads or optical sensors. The rail is configured to permit movement of the mobile device, when driven by an external drive mechanism, along a main scanning direction but prohibits rotational movement of the mobile device. In this fashion, the mobile device remains substantially at the same measured distance from the flat surface of an object, e.g., moving sheet or web, being analyzed.

Abstract: A compact, long lasting sensor for measuring components such as moisture in moving sheets including paper in a papermaking apparatus employs light sources that produce radiation within defined wavelength regions of interest and the light sources are modulated at high frequencies using non-mechanical techniques. A single detector with various radiation sources can measure at all frequencies while keeping information separated. Superluminescent light emitting diode or laser diode light sources can be directly electrically modulates for improved noise rejection. These higher power and bright light sources afford excellent fiber optic launch efficiency and permits the sensor to be scanned at much faster rates over the paper being monitored.

Abstract: A scanning system includes a cable take-up mechanism that uses a series of pulleys that determine the bend diameters of a scanning system. The mechanism is particularly suited for a spectrometric, e.g., infrared, scanning system where moving scanner or sensor head essentially houses only the optical elements while essentially of all the other electronic and optical components associated with the measurement are housed in an easily accessible compartment that is remote from the moving scanner head. Light is transmitted through optical fiber cables. The cable take-up mechanism maintains the fiber optic cable at essentially constant total bend length and bend diameter thereby minimizing any dynamic changes to spectral bend losses as the optical head is scanned. The light weight construction of the sensor head further reduces vibrations associated with the moving scanner head.