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:

• Step 1:
• an acceptable concentration threshold a % and a reference concentration auxiliary threshold X % of a target gas in a glass bottle are acquired, and by using the wavelength modulation spectroscopy (WMS) detection method in the current environment, second harmonic peaks P0, Pa, PX in the glass bottle are respectively acquired under the concentrations of 0%, a %, X %, wherein 0%<X %<a %;
• Step 2:
• an absolute value is calculated for the different between the second harmonic peaks P0 and Pa to get Da, and an absolute value is calculated for the different between the second harmonic peaks P0 and PX to get Dx;
• Step 3:
• quality inspection is performed for the glass bottle to be detected on the basis of the difference Da and Dx in Step 2 as follows:
• Step 31:
• the second harmonic peaks are collected for the glass bottle to be detected 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 Step S32, otherwise the glass bottle is unacceptable and the detection is performed on the next glass bottle to be detected;
• Step 32:
• it is determined 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 elements are null;
• and for adding new elements, old elements are sequentially discarded;
• Step 33:
• a mean PL of elements in the current queue L is calculated, and the second harmonic peak Pa under the acceptable concentration threshold a % is updated with the sum of the mean PL and the difference Da, and the second harmonic peak PX under the reference concentration auxiliary threshold X % is updated with the sum of the mean PL and the difference Dx, wherein the updated data is used to detect the next glass bottle to be detected following Steps S31-S33.