Abstract: In a solids profile measurement system for determining the quality of a solids bed formed from a liquid-solid slurry in a vessel, a sensor adapted to generate signals indicative of a profile as measured by progressively immersing the sensor deeper into the slurry is provided. An extension mechanism, at least a portion of which is coupled at one end to the sensor and at an opposite end to a piece of processing equipment, is provided to affect retrograde movement in a first direction to immerse the sensor in a slurry, and in a second direction opposite the first direction. A controller in communication with the extension mechanism is also provided and issues commands thereto and receives signals generated by the sensor.