Designed to correlate with traditional titration methods, the Vapor Pro Rx provides a fast, chemical-free way to accurately check moisture in sealed vials of lyophilized materials, without disturbing the vial’s integrity. The unit also eliminates the problems associated with the expensive glassware and toxic reagents required for traditional titration methods. The unit utilizes a sealed flow-path, including a sleeved sampling needle, which is continuously purged with dry carrier gas. This innovative design gives no opportunity for moist air to enter or trap itself within the system. In addition, the moisture-specific sensor is not influenced by other volatiles. This patented process produces accurate readings of the sample’s moisture content down to 10 ppm (or .001 percent moisture) on samples as small as 5 milligrams, without the addition of ambient air humidity or other volatiles burned off during the test. Results are achieved in as few as 3 minutes and may be displayed as percent moisture, parts per million moisture, or micrograms of water.