Abstract: A fiber optic fluid opacity sensor includes a light source (12) transmitting light to dividing means (14) for providing a sample light signal (18) and a reference light signal (20) to dual photodetectors (26, 28). Sample and reference optical pathways (19, 21) are defined by optical fibers (18, 20) spaced apart from and axially aligned with the photodetectors (26, 28) at a predetermined distance. Signal processing means (30) takes the log ratio output of the signals from the photodetectors (26, 28) for cancelling the effect of light source drift since the same source (12) is common to both for measuring the light transmission and determining opacity therefrom. A sample probe (40) contains the photodetectors (26, 28) and the sample and reference optical pathways (19, 21). The light source (12) and the signal processing means (30) are situated outside of the probe (40) and by virtue thereof outside of the sample process line (48).

Abstract: Nails having one or more washers positioned between the nail head and the face of the mold are inserted into the vents of tire molds. The washered nails prevent rubber protrusion from forming in the vents during molding, but allow the escape of air.

Abstract: Nails are inserted into the vents of tire molds. The nails prevent rubber protrusion from forming in the vents during molding.