Tubular Device
The tubular device, a sealed permeable tube containing the desired permeant gas, is
the most widely used of the various permeation devices. Release of the chemical fill
occurs by permeation through the wall 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.
We can supply tubular permeation devices with active lengths (the length of the permeable
section) ranging from 0.5 cm to 20 cm.
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 with 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.
Wafer Device
Wafer devices have only a small permeable window, or wafer, so permeation rates
are typically lower than rates for tubular devices by an order of magnitude. Since
permeation occurs only through the polymeric wafer, the permeation rate is controlled
by varying the wafer material, the thickness of the wafer, and the diameter of the
permeation opening. Gases whose high vapor pressure at normal permeation
temperatures prevent their containment in a tubular device can be contained in a wafer
device. Wafer devices are available in different styles to allow use in calibrators made
by various manufacturers.
Types of Devices
Typical Compounds
Ammonia
Benzaldehyne
Benzene
Carbon Disulfide
Chlorine
Dimethyl Sulfide
Ethanol
Formaldehyde
Freons
Hydrogen Fluoride
Hydrogen Sulfide
Literally hundreds of compounds are available in permeation devices. Some of the
most typical compounds include:
Isopropyl Alcohol
Mercury
Methanol
Methyl Bromide
Nitrogen Dioxide
Phenol
Sulfur Dioxide
Sulfur Hexafluoride
Toluene
Water
Xylene
More Information
More useful information can be found in TechNote 1001:
Generating Calibration Gas
Standards with Dynacal Permeation Devices
, and TechNote 1002:
Generating a Part
Number for a Dynacal Permeation Device
. These can be found in the support section
of www.vici.com.
US customers
call toll-free
(877) 737-1887
VICI
®
is a registered trademark of Valco Instruments Co. Inc. and VICI AG. Dynacalibrator
®
and Dynacal
®
are registered trademark of VICI Metronics, Inc
Teflon
®
is a registered trademark of E.I. duPont de Nemours. Pyrex
®
is a registered trademark of Corning Glass.
North America, South America, and Australia/Oceania contact:
Europe, Asia, and Africa contact:
Metronics Inc.
tel: 360 697-9199
fax: 360 697-6682
metronics@vici.com
VICI AG International
rev 5/03
PB-023 permtube
tel: Int + 41 41 925-6200
fax: Int + 41 41 925-6201
info@vici.ch
Website : www.chromtech.net.au E-mail : info@chromtech.net.au TelNo : 03 9762 2034 . . . in AUSTRALIA