Illuminance calibration device and method thereof

An illuminance calibration method, comprising:

• detecting a current illuminance of a target position by a light detecting module;
• receiving the current illuminance by a processing module;
• transmitting a test signal to a lighting device to adjust a brightness of the lighting device by a minimal brightness adjusting unit of the lighting device by the processing module so as to obtain an adjusted current illuminance of the target position;
• deducting the current illuminance from the adjusted current illuminance by the processing module to obtain a brightness-illuminance relation parameter;
• deducting the current illuminance from a target illuminance by the processing module to obtain a first calculation result;
• multiplying the first calculation result by the minimal brightness adjusting unit by the processing module to obtain a second calculation result;
• dividing the second calculation result by the brightness-illuminance relation parameter by the processing module to obtain a third calculation result in order to serve as a target brightness of the lighting device;
• generating a brightness adjusting signal according to the target brightness and the minimal brightness adjusting unit by the processing module;
• and
• adjusting the brightness of the lighting device according to the brightness adjusting signal by the processing module in order to make an illuminance of the target position reaches the target illuminance.