Abstract: A method of controlling a concentration or range of concentrations of a liquid or gas in an enclosure is provided. The method includes positioning an injection station within the enclosure. the injection station includes a liquid or gas source, a sprayer assembly and a system that delivers the liquid or gas from the liquid or gas source to the sprayer assembly. A concentration level of the liquid or gas in the environment surrounding the injection station is monitored using a sensor and the sensor providing a signal indicative of the concentration level to a controller. The controller controls the flow of the liquid or gas to the sprayer assembly based on the signal.

Abstract: A liquid measuring device for dispensing measured volumes of liquid from a source of liquid under pressure is disclosed and includes a cylinder, a free piston for reciprocal traveling in the cylinder. In accordance with the present invention, the piston has a specific gravity that is adjusted to approximately match the specific gravity of the liquid thus improving the precision and accuracy of the dispensing device.