Gastec are leading gas detector tubes manufacturer based in Japan and deliver worldwide. Gastec offer a low-cost method of gas detection that provide a visual and indicative gas measurement. a1-cbiss are Gastec’s largest distributor of detector tubes in the UK. a1-cbiss deliver a slick operation and a huge volume of Gastec detector tube stock available on a next day delivery for our customers.

Gastec Information

Gastec gas detection tubes utilise colorimetric technology to perform spot sampling of around 300 hazardous and toxic gases, and chemical vapours in industrial environments.

Gastec gas detector tubes provide a quick identification of gases. Fume hood confined space gas or COSHH assessments are among the most common uses.

You can also quickly search detector tube availability using our online stock check tool.

There are 10 tubes in a pack except for GAS31B (Oxygen). The standard tubes require an air sample to be drawn using the Gastec Sampling Pump (bought separately).

How is gas detected using the Gastec gas detector tube system?

Gastec gas detector tubes are generally supplied in packs of ten, and are sealed at both ends. In operation, the tips are broken off using a tube tip breaker, a neat function often within the hand pump or otherwise sold as a separate item. Standard gas detector tubes are used with a handheld air sampling pump.

Depending on the manufacturer, the pump utilises either a bellows or piston design. The pump connects to one end of the detector tube and the user draws a sample of 50ml or 100ml of ambient air. As the gas sample works its way up the tube towards the sampling pump, it reacts with the chemical reagent within the tube.

The colour stain produced is proportional in length to the concentration. By using a calibration scale printed on the tube, the concentration may be read immediately, without the need for laboratory analysis. The point where this reaction stops is easily read off against markings on the gas detector tube.

What range do the detector tubes measure at?

For many gases and vapours, there are several concentration ranges available (ppm, %, Mg/m3, mg/l) giving you the flexibility to measure both low and high concentrations without sacrificing precision.

What do the most popular standard detector tubes test for?

Hydrogen Sulphide and Carbon Monoxide are our most popular standard detector tube types. There are 7 variations of Hydrogen Sulphide detector tubes within the standard tubes classification. The main difference being the range at which they detect. All standard detector tubes are priced at the same price no matter the detection range. There are 8 different Carbon Monoxide detector tube range types.

Do short term gas detector tubes comply with standards?

Yes, European Standard EN1231 specifies performance requirements and test methods under prescribed laboratory conditions for length-of-stain detector tubes and their associated pump (detector tube measurement system) used for short term measurements of the concentration of specified chemical agents in workplace air.

What are Gastec Gas Detector Tubes?


Gastec tubes as they’re known are glass tubes that are filled with chemical reagent that absorbs and reacts with the target gas or vapour being measured as part of a gas detection programme. A colorimetric stain (a colour change) is created. For most Gastec Standard tubes, the concentration is read directly from the measurement scale on each tube. The detector tube system is comprised of a handheld air sampling pump and detector tubes.

What is the purpose of Gastec Gas Detector Tubes?

The Gastec tube system is a complete sampling and analysis system for determining hazardous gas and vapour concentrations quickly and easily. The majority of activities that the detector tube system is used for is to carry out spot sampling e.g. to check the level of hazardous gas within a container that has been unloaded from a ship or for determining the level of hazardous gases present on-site. It is not advised to use Gastec tubes for personal safety as they don’t provide an alarm or warning system.

What are the benefits of Gastec tubes?

 Gastec gas detector tubes are most effective for accurate on-the-spot measurements
Relatively inexpensive
Intrinsically safe method, allowing them to be deployed in all applications where some gas detectors cannot