Rechner Sensors has a new sensor, the KA700, which has a temperature rating of 120 Celsius (248 Fahrenheit). It has a polyamide housing, with high resistance to abrasion, and granular material is not an issue. It is a full potted sensor, that does not have high vibration problems. It is designed for dryer applications.
-Watertight and dust tight (IP67);
-Voltage of 12 to 30 VDC;
-20 turn trim pot; and,
-Long sensing range of two to 25mm