Abstract: An optical attenuation measurement system is provided for obtaining signals proportional to movement of a system to which it is attached. The measurement system includes a light source positioned within a length of conduit in which the light emitted will produce multiple reflections. A fiber optic cable is slidably disposed within the conduit to transmit the radiation emitted from the light source gathered thereby. The relative displacement of the fiber optic cable to the light source produces a signal as a function of this displacement which is converted into electrical signals by a light detecting element at the opposite end of the cable. The system is particularly useful to form an interactive device for control of a remote intelligent machine, robot or the like. For example, the system may be used on an operator's hand to detect movement of the hand and fingers for controlling a robotic hand which will mimic the operator's hand movements.

Abstract: A method and apparatus are disclosed for measuring the amount of binder or of a particular constituent of that binder dispersed within a fibrous mat. The binder may typically be a suspension of one or more solids in a liquid carrier such as water. A radiation source is provided at a first wave length which is highly responsive to the presence of the binder constituent dispersed within the mat. A second radiation source is provided at a second wave length which is substantially insensitive to the presence of the binder constituent within the mat. A ratio is taken of the transmitted energy at these two wave lengths through the mat and this ratio is used as an indication of the amount of the binder constituent. A third source of radiation and a third wave length is transmitted through the mat to provide an indication of the thickness or density of the mat, the third wave length being substantially unaffected by the presence of the binder constituent in the mat.