Appendix F1
United Kingdom
Determination of the linear velocity of the gas
Inject 1-3 μl methane (or propane) into the GC apparatus after it has been regulated to normal operating conditions. Measure the time it takes for the gas to flow through the column from the time it is injected to the time the peak appears (t M ).
The linear velocity in cm/s is given by the formula L/t M , where L is the length of the column in cm and t M the time measured in seconds.