Residual amount management device outputting information for guiding supply of printing consumable into tank

A residual amount management device for managing a residual amount of a printing consumable for a printing device, the printing device including:

• a tank configured to store the printing consumable supplied from a storage body having a predetermined capacity for storing a printing consumable;
• a level sensor configured to detect whether a level of the printing consumable in the tank is higher than or equal to an intermediate reference level, the intermediate reference level corresponding to an intermediate portion of the tank in a vertical direction;
• and a print engine configured to perform image formation on a printing medium by using the printing consumable in the tank,
• the residual amount management device being configured to perform:
• a printing amount obtaining process including:
• obtaining printing-amount information indicating a printing amount of the printing consumable consumed by image formation using the print engine;
• a first determining process in response to detection, by the level sensor, that the level of the printing consumable in the tank has increased from below the intermediate reference level to at or above the intermediate reference level, the first determining process including:
• determining that the printing consumable is supplied into the tank from the storage body;
• a second determining process in response to detection, by the level sensor, that after the first determining process, the level of the printing consumable in the tank becomes lower than the intermediate reference level during the image formation, the second determining process including:
• determining whether a difference between a current estimated amount and a current detection amount is greater than or equal to a predetermined amount, the current estimated amount being calculated using the printing-amount information obtained in the printing amount obtaining process, the current estimated amount being calculated in response to determining that the printing consumable is supplied into the tank in the first determining process, the current detection amount being based on detection, by the level sensor, that the level of the printing consumable becomes lower than the intermediate reference level;
• and
• a supply guidance process in a case where the difference is determined to be less than the predetermined amount in the second determining process, the supply guidance process including:
• outputting supply-guidance information for guiding a supply of a printing consumable into the tank.