Testing device and method of use

摘要

Method for controlling movement of a liquid from a first location to a second location via a dispenser for the liquid located in a liquid line between the first and second location. The dispenser includes a nozzle, an internal liquid conduit, a valve, a body portion, a hollow annular collar and a first detector. The first detector is located in the collar which is positioned around the nozzle or between the nozzle and the body portion such that the first detector is in vapor communication with a vapor space above the second location. The vapor from the vapor space is analyzed by withdrawing the vapor past the first detector and using the results of the analysis to control the operation of the valve.