Chemical mixer tank calibrator and calibrating method for the same

A method for calibrating a chemical mixer tank used in a chemical supplying device, wherein the chemical mixer tank is connected to a buffer tank through a conveying pipe, the method comprising:

• a) setting an initial reference of a reference value Y to zero;
• b) activating a mixer tank pump to convey chemical from the mixer tank to the buffer tank when a liquid level is lower than a first level of the buffer tank, otherwise, iterating steps a) and b);
• c) activating the mixer tank pump for about 1 minute to about 5 minutes;
• d) stopping calibrating when the liquid level reaches a second level, wherein the second level is higher than the first level, otherwise, proceeding to a next step e);
• e) initiating a step motor for performing a weight calibration on the chemical mixer tank by lifting the mixer tank upward so as to reduce a reading from a weight measurement, and adding one to the reference value Y;
• f) repeating steps c) to e) until Y reaches five;
• g) initializing the step motor;
• and
• h) triggering the alarm.