Precise standard calibration gas ensures precise measurements
Calibration gas
Precise calibration is the lifeline of a detector tube. GASTEC takes particular pride in the painstaking care it takes to keep any concentration fluctuations due to possible adherence of gas molecules to the inside of the storage or transfer vessels to an absolutely insignificant minimum. GASTEC is always on the cutting edge of new developments and technologies as it was quick to adopt innovative and accurate calibration gas generating methods such as the permeation tube or the gas diffusion tube principles. GASTEC is highly regarded also as a pioneer of calibration gas technology.
Permeation tube |
A permeation tube is a sealed tube, that has a uniform inner diametre, is filled with a highly pure liquefied target gas, and is extremely stable. If the permeation tube is maintained at a fixed temperature in our proprietary calibration gas generating equipment, liquefied gas will permeate from the detector tube at a fixed flowrate. When this combines with a fixed quantity of dilution gas, calibration gas of the desired concentration is continuously generated. |
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Diffusion tube | A diffusion tube is a glass tube that consists of a liquid container and a diffuser with a uniform inner diametre. A pure and very stable target liquid is put into the liquid container using a glass syringe. If the tube is kept at a constant temperature, the liquid evaporates and diffuses at a constant rate and mixes with the dilution gas whereby the calibration gas of the desired concentration is continuously generated. |
High pressure gas cylinder | Calibration gases are supplied in high-pressure gas cylinders, which have been prepared in accordance with Japanese Industrial Standard JIS K0001 to K0007. |
Static dilution | With this method, a prescribed amount of highly purified gas or liquid of the target substance is placed in a glass container (20 litres or more), and is diluted with air or nitrogen gas to generate the desired concentration of target gas. |
Dynamic dilution | With this method, the flowrate of a precisely determined concentration of target gas and of the dilution gas are regulated to continuously generate the desired concentration of the target gas. |
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About gas detector tubes
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General information on gas measurement
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Reference