Permeation devices are small, inert capsules containing a pure chemical compound in a two phase equilibrium between its gas phase and its liquid or solid phase
Permeation devices are small, inert capsules containing a pure chemical compound in a two phase equilibrium between its gas phase and its liquid or solid phase. At a constant temperature, the device emits the compound through its permeable portion at a constant rate.
Permeation devices are typically inserted into a carrier flow to generate test atmospheres for calibrating gas analyzer systems, testing hazardous gas alarms, or conducting long-term studies of effects on materials or biological systems - in short, any situation requiring a stable concentration of a specific trace chemical.
The tubular device, a sealed permeable cylinder containing the desired permeant gas, is the most widely used of the various permeation devices. Release of the chemical occurs by permeation through the walls of the Teflon tube for the entire length between the impermeable plugs. A wide range of rates can be achieved by varying the length and thickness of the tube, with typical rates ranging from 5 ng/min to 50,000 ng/min.
Extended life tubular device
Our unique extended life tubular (XLT) device is essentially a standard tubular device coupled to an impermeable stainless steel reservoir. This design offers a range of permeation rates corresponding to a tubular device but has a significantly enhanced lifetime - by a factor of 3 for a 5 cm (active length) device or a factor of 12 for a 1 cm device.
VICI Metronics, Inc., 2991 Corvin Drive, Santa Clara, CA 95051. Tel: 408-737-0550; Fax: 408-737-0346.