Material supply system, a storage medium storing a program for a material supply system and material supply method

A non-transitory storage medium storing a program used in a material supply system that is equipped with a tank containing a liquid material and with a liquid level sensor that is provided inside the tank, wherein the liquid level sensor is a self-heating type of sensor that, in a state in which the liquid level sensor is generating heat as a result of being supplied with a first predetermined current, voltage, or power, detects a liquid surface, wherein

• the material supply system comprises a constant current/voltage/power circuit that switchably supplies a first constant current, voltage, or power and a second constant current, voltage, or power lower than the first constant current, voltage, or power to the liquid level sensor, and
• the program causes a computer to function as:
• a monitoring portion that monitors a temperature of the liquid level sensor obtained based on an output signal from the liquid level sensor;
• and as
• an energy control portion that, in a case in which the temperature of the liquid level sensor monitored by the monitoring portion reaches a predetermined upper limit value, performs a protective operation that controls the constant current/voltage/power circuit to switch the current, voltage, or power supplied to the liquid level sensor from the first constant current, voltage, or power to the second constant current, voltage, or power to protect the liquid level sensor,
• the first constant current, voltage, or power is supplied to the liquid level sensor during a normal operation in which the temperature of the liquid level sensor monitored by the monitoring portion does not reach the predetermined upper limit value, and
• the second constant current, voltage, or power is supplied to the liquid level sensor during the protective operation.

A material supply method that uses a material supply system that is equipped with a tank containing a liquid material and with a liquid level sensor that is provided inside the tank, wherein the liquid level sensor is a self-heating type of sensor that, in a state in which the liquid level sensor is generating heat as a result of being supplied with a first predetermined current, voltage, or power, detects a liquid surface, wherein the material supply system comprises a constant current/voltage/power circuit that switchably supplies a first constant current, voltage, or power and a second constant current, voltage, or power lower than the first constant current, voltage, or power to the liquid level sensor, the method comprising:

• a monitoring step in which a temperature of the liquid level sensor obtained based on an output signal from the liquid level sensor is monitored;
• and
• an energy control step in which, in response to the monitored temperature of the liquid level sensor reaching a predetermined upper limit value, a protective operation is performed by controlling the constant current/voltage/power circuit to switch the current, voltage, or power supplied to the liquid level sensor from the first constant current, voltage, or power to the second constant current, voltage, or power to protect the liquid level sensor, wherein
• the first constant current, voltage, or power is supplied to the liquid level sensor during a normal operation in which the temperature of the liquid level sensor monitored by the monitoring portion does not reach the predetermined upper limit value, and
• the second constant current, voltage, or power is supplied to the liquid level sensor during the protective operation.

A material supply system comprising:

• a tank containing a liquid material;
• a liquid level sensor that is provided inside the tank, wherein the liquid level sensor is a self-heating type of sensor that, in a state in which the liquid level sensor is generating heat as a result of being supplied with a first predetermined current, voltage, or power, detects a liquid surface;
• a pressure sensor that detects pressure inside the tank;
• a constant current/voltage/power circuit that switchably supplies a first constant current, voltage, or power and a second constant current, voltage, or power lower than the first constant current, voltage, or power to the liquid level sensor;
• and
• an energy control portion that, in a case in which a pressure value detected by the pressure sensor falls below a predetermined threshold value, performs a protective operation that controls the constant current/voltage/power circuit to switch the current, voltage, or power supplied to the liquid level sensor from the first constant current, voltage, or power to the second constant current, voltage, or power to protect the liquid level sensor, wherein
• the first constant current, voltage, or power is supplied to the liquid level sensor during a normal operation in which the pressure value detected by the pressure sensor does not fall below the predetermined threshold value, and
• the second constant current, voltage, or power is supplied to the liquid level sensor during the protective operation.

A material supply system comprising:

• a tank containing a liquid material;
• a single liquid level sensor that is provided inside the tank, wherein the single liquid level sensor is a self-heating type of sensor that, in a state in which the single liquid level sensor is generating heat as a result of being supplied with a first predetermined current, voltage, or power, detects a liquid surface;
• a monitoring portion that monitors an output signal from the single liquid level sensor or a temperature of the single liquid level sensor obtained based on the output signal;
• a constant current/voltage/power circuit that switchably supplies a first constant current, voltage, or power and a second constant current, voltage, or power lower than the first constant current, voltage, or power to the single liquid level sensor;
• and
• an energy control portion that, in a case in which the output signal or the temperature of the single liquid level sensor monitored by the monitoring portion reaches a predetermined upper limit value, performs a protective operation that controls the constant current/voltage/power circuit to switch the current, voltage, or power supplied to the single liquid level sensor from the first constant current, voltage, or power to the second constant current, voltage, or power to protect the single liquid level sensor, wherein
• the first constant current, voltage, or power is supplied to the single liquid level sensor during a normal operation in which the output signal or the temperature of the single liquid level sensor monitored by the monitoring portion does not reach the predetermined upper limit value, and
• the second constant current, voltage, or power is supplied to the single liquid level sensor during the protective operation.