The Opto-Port is a patented sampling device for use with the SMART III NIR Moisture Sensor. The Opto-Port can perform moisture measurement of powdered materials within a closed conveying system such as within pneumatic piping or under a rotary airlock valve. Installed directly into the conveying system, the stainless steel Opto-Port is attached to a NIR Sensor. Product moisture is read through a quartz window at the end of the Opto-Port (usually inside a drop pipe). A regulated air blast instantly removes old product from the measurement window so that a new reading is taken every 3-5 seconds. No moving parts are necessary to make the moisture measurement.