Method for detecting gas concentration in glass bottle with dynamical threshold adjustment

A method for detecting gas concentration in a glass bottle with dynamical threshold adjustment, comprising:

• acquiring an acceptable concentration threshold a % and a reference concentration auxiliary threshold X % of a target gas in a glass bottle, and acquiring second harmonic peaks P0, Pa, PX in the glass bottle respectively under the concentrations of 0%, a %, X % by using a wavelength modulation spectroscopy (WMS) detection method in a current environment, wherein 0%<X %<a %;
• calculating an absolute value for a difference between the second harmonic peaks P0 and Pa to get Da, and calculating an absolute value for a difference between the second harmonic peaks P0 and PX to get Dx;
• performing quality inspection on a glass bottle to be detected based on the differences Da and Dx in the calculating as follows:
• collecting the second harmonic peaks for the glass bottle to be detected by using the WMS detection method in order to determine whether the peaks are less than or equal to the second harmonic peak Pa under the acceptable concentration threshold a %, and, if so, the glass bottle to be detected is an acceptable medicinal bottle and the process proceeds to determining whether the second harmonic peak, otherwise the glass bottle is unacceptable and the detection is performed on a next glass bottle to be detected;
• determining whether the second harmonic peaks of the glass bottle to be detected are less than or equal to the second harmonic peak PX under the reference concentration auxiliary threshold X %, and, if so, the second harmonic peaks of the glass bottle to be detected are sequentially added into a queue L;
• wherein the queue L has a length of M, and the first element in the initial queue L is equal to the second harmonic peak P0 while the rest of the elements are null;
• and for adding new elements, old elements are sequentially discarded;
• calculating a mean PL of elements in the current queue L, and updating the second harmonic peak Pa under the acceptable concentration threshold a % with the sum of the mean PL and the difference Da, and updating the second harmonic peak PX under the reference concentration auxiliary threshold X % with the sum of the mean PL and the difference Dx;
• collecting second harmonic peaks for a current glass bottle to be detected by using the WMS detection method;
• and
• determining whether the current glass bottle to be detected is an acceptable medicinal bottle based on the collected second harmonic peaks for the current glass bottle to be detected, the updated second harmonic peak Pa, and the u dated second harmonic peak PX.