Methods, devices, and systems for controlling the rate of gas depressurization within a vial containing a gas sample

A method for controlling a rate of gas depressurization within a vial having a head space to be sampled by a head space sampling device, said head space sampling device having a ventilation pathway connectable in fluid communication with a lower pressure environment, and a sample loop connectable between and in fluid communication with said head space and said ventilation pathway, said method comprising:

• establishing fluid communication between said sample loop and said head space;
• establishing a sample gas pressure within said head space, said sample gas pressure being greater than the pressure in said lower pressure environment;
• connecting said sample loop in fluid communication with said lower pressure environment through said ventilation pathway;
• venting gas from said head space through said sample loop to said lower pressure environment, thereby allowing sample gas to flow from said head space to said sample loop, to provide a predetermined rate of gas depressurization within the head space and sample loop;
• and
• monitoring the sample gas pressure within said head space, wherein gas is vented from said head space through the sample loop to said lower pressure environment, such that said sample gas pressure within said head space gradually decreases to a predetermined pressure setpoint,
• wherein the pressure of sample gas in said head space and sample loop is directly controlled by said predetermined rate of gas depressurization and said predetermined pressure setpoint is less than the initial sample gas pressure.

A method for controlling a rate of gas depressurization within a vial having a head space to be sampled by a head space sampling device, said head space sampling device having a ventilation pathway connectable in fluid communication with a lower pressure environment, and a sample loop connectable between and in fluid communication with said head space and said ventilation pathway, said method comprising:

• establishing fluid communication between said sample loop and said head space;
• establishing a sample gas pressure within said head space, said sample gas pressure being greater than the pressure in said lower pressure environment;
• connecting said sample loop in fluid communication with said lower pressure environment through said ventilation pathway;
• and
• venting gas from said head space through said sample loop to said lower pressure environment, thereby allowing sample gas to flow from said head space to said sample loop, to provide a predetermined rate of gas depressurization within the head space and sample loop,
• wherein the pressure of sample gas in said head space and sample loop is directly controlled by said predetermined rate of gas depressurization to a predetermined head space pressure setpoint less than the initial sample gas pressure,
• wherein said predetermined rate of gas depressurization is substantially linear.