Monitoring with a radially magnetized magnet and hall effect sensor

A steam cooker comprising:

• a cabinet having a cooking chamber accessible through a door, the cabinet substantially sealed when the door is closed;
• a reservoir in fluid communication with the cooking chamber;
• and
• a level sensing assembly comprising:
• a float body buoyant on a quantity of water, the float body positioned within the reservoir,
• a radially magnetized magnet having an interior bore with a first magnet pole and an exterior surface radially opposite the interior bore, the exterior surface having a second magnet pole opposite the first magnet pole;
• and
• a Hall effect sensor sized to be translated axially with respect to the radially magnetized magnet along a range of axial travel within the interior bore of the radially magnetized magnet to produce an output, the magnitude of the output varying substantially linearly with respect to a varying axial position of the Hall effect sensor along the range of axial travel;
• and
• a controller programmed to receive the output from the Hall effect sensor and determine a level of a fluid corresponding to the axial position of the Hall effect sensor along the range of axial travel, the controller programmed to:
• enter a cook mode when the signal is within a threshold nominal range corresponding to a normal operating range of the level of fluid,
• enter an overfill mode when the signal is above the threshold nominal range corresponding to the level of fluid above the normal operating range, and
• enter a low-fill mode when the signal is below the threshold nominal range corresponding to the level of fluid below the normal operating range;
• and
• a heater operably connected to the controller, the controller programmed to allow activation of the heater when the controller is in the cook mode, and to prevent activation of the heater when the determined level of fluid is in the overfill mode or the low-fill mode.

A method of assessing the operational state of a fluid-interactive appliance, the method comprising:

• receiving an analog signal from a Hall effect sensor disposed within an inner bore of a radially magnetized magnet, the magnitude of the analog signal varying substantially linearly with respect to a varying axial position of the Hall effect sensor along a range of axial travel within the inner bore of the radially magnetized magnet, the radially magnetized magnet fixed to a float that is buoyant on a fluid in a reservoir,
• processing the analog signal to determine the axial position of the radially magnetized magnet and the float relative to the Hall effect sensor,
• determining a level of a fluid within the reservoir from the axial position of the float as a function of the substantially linear analog signal, wherein:
• enabling heater operable to boil water in the reservoir if the step of determining comprises determining the fluid contained in the reservoir is within a threshold fill level range, and
• disabling the heater if the step of determine comprises determining the fluid contained in the reservoir is either above or below the threshold fill level range.