The Teflon-coated spike bob is designed for measuring powders and solids material that may adhere to the sensor probe. It is ideal for use in sticky materials such as silica or frac sand, powdered chemicals or minerals, additives and ingredients, or any material that tends to build up on the sensor probe. The Teflon coating on the probe has US FDA approval which also enables it to be used in bins, tanks, or silos containing ingredients used in animal and human food processing or pharmaceutical environments.