Sheet product dispenser with product level indicator calibration

A method of calibrating a product depletion curve for a sheet product dispenser, the method comprising:

• receiving an indication that a product roll was installed in the sheet product dispenser, wherein the sheet product dispenser comprises a dispensing mechanism configured to receive sheet product from the product roll and dispense a portion of the sheet product from the product roll;
• operating a sensor to emit and receive a signal, wherein the sensor is configured to emit the signal toward the product roll and receive the signal, wherein the signal is reflected off a surface of the product roll;
• determining a time-of-flight of the signal that correlates to a time period from when the signal was emitted by the sensor to when the signal was received by the sensor;
• determining an expected characteristic of a theoretical signal for a theoretical full product roll installed in the sheet product dispenser, wherein the expected characteristic comprises at least one of an expected time-of-flight of the theoretical signal and an expected distance to the surface of the theoretical full product roll;
• comparing a characteristic of the signal to the expected characteristic of the theoretical signal, wherein the characteristic of the signal is at least one of the time-of-flight of the signal or a distance to the surface of the installed product roll, wherein the distance is determined based on the time-of-flight of the signal;
• and
• adjusting the product depletion curve based on the comparison.

A sheet product dispenser comprising:

• a housing configured to receive a product roll for dispensing from the sheet product dispenser, wherein the product roll comprises a roll of sheet product and defines a cylindrical shape with a diameter and an outer surface;
• a sensor positioned within the housing and configured to emit a signal toward the outer surface of the product roll and receive a reflection of the signal after the signal bounces off the outer surface of the product roll, wherein the product roll is positioned within the housing such that, as sheet product is dispensed from the product roll, the diameter of the product roll decreases and the outer surface moves further away from the sensor;
• and
• a controller configured to:
• operate the sensor to emit the signal and receive the reflection of the signal;
• determine a time-of-flight of the signal that correlates to a time period from when the signal was emitted by the sensor to when the reflection of the signal was received by the sensor;
• compare at least one of the determined time-of-flight of the signal or a distance to the outer surface of the product roll determined using the determined time-of-flight to a corresponding predetermined time-of-flight or predetermined distance, wherein the predetermined time-of-flight is associated with an expected predetermined time-of-flight for a theoretical product roll installed in the housing, wherein the predetermined distance is associated with an expected distance from the sensor to a theoretical product roll installed in the housing;
• and
• adjust a product depletion curve based on the comparison.