Research on leak detection of vials based on tunable diode laser absorption spectroscopy technology

The off-line sampling destructive test is often used in the seal integrity test of vials, which has the disadvantages of long time consuming, low accuracy and high missing rate. In order to solve the above problems, the tunable diode laser absorption spectroscopy technology and wavelength modulation spectroscopy technology are used to measure the oxygen concentration in the vials. The ratio method of second harmonic and first harmonic is used to eliminate the influence of the rapid change of light intensity. The experimental results show that the system can complete the seal integrity detection of 300 vials per minute. This method belongs to the non-destructive online detection mode, which can realize the fast detection of vials without interference.