Patent ID: 7537018

Claim:
An apparatus for creating and maintaining a partial vapor pressure in a sample chamber of a sorption analyzer, comprising: a first mass flow controller providing a first dry gas flow; a saturator configured to saturate the first dry gas flow into a near-saturated gas flow, an output of the saturator in fluid communication with an input of the sample chamber; a second mass flow controller providing a second dry gas flow; a two-way valve in fluid communication at an output end of the two-way valve with an outside atmosphere; and a three-way valve comprising an input port in fluid communication with an output of the first mass flow controller, a first output port in fluid communication with an input of the saturator, and a second output port in fluid communication with the input of the sample chamber and the output of the saturator, an output of the second mass flow controller, and an input end of the two-way valve, wherein, in a first mode of operation, the first dry gas flow provided from the first mass flow controller is configured to pass through the three-way valve before entering the saturator.