We are official distributor for SEMA Gases and GMS Instruments.

We have a wide range of instruments like pressure gauges, thermometers etc. and SEMA gases (span Gases)  in stock.

Calibration gas is used to calibrate gas analysers or gas detectors. All SEMA calibration gases are traceable according to national (Dutch) as well as international criteria. SEMA Gases delivers multiple types of calibration gases (10L, 34L, 58L, 110L) out of stock suitable for the shipping industry, offshore industry, chemical industry, laboratories, and universities.

Gas mixtures are any combination of two or more gas components, compressed into one cylinder. At SEMA Gases we only work with the best of the best. This means it is no problem to compose a mixture of two or 30 different components. And all of that against the best price and service possible.

SEMA Gases is originally a Dutch brand of span gases in disposable cylinder cans started from the desire to create a brand which applies to all brands of gas detection equipment. Our products are used for calibration of portable gas detection instruments and calibration of fixed gas detection systems. SEMA Gases produces single gases (flammable gases, oxygen, toxic gases) and gas mixtures (2, 3, 4 or 5 gas mixtures) in various cylinder sizes 10 ltr, 34 ltr, 58 ltr or 110 ltr. SEMA Gases also supplies the corresponding flow regulator valves with different flow rates and thread connections. Manual type flow regulators are used for diffusion-type gas detecting instruments which do not have a pump or with a hand pump. Demand flow regulating valves are used for gas detection instruments with an internal (or external) pump. SEMA Gases also supplies accessories like gas sampling bags, sampling hoses, calibration adapters and carrying cases.

Calibration gas is a reference gas or a mixture of gases which are usually compressed. The composure of calibration gas exists of one initial gas and is enhanced by one or more component(s). Calibration gas is used to calibrate gas analysers or gas detectors. All SEMA calibration gases are traceable according to national (Dutch) as well as international criteria. Calibration gas can be divided into two categories; zero calibration and span calibration.

Zero calibration gas is a gas which is free from flammable gases. Zero calibration gases are performed when gas detection or gas analysers get calibrated with none of the analyte gas structures to which the analyser or detector will respond. For example, a zero calibration of an oxygen-, or carbon dioxide analyser can be performed with pure nitrogen. Because nitrogen does not hold either oxygen or carbon dioxide, a zero point can be confirmed this way.

A span calibration is a more advanced type of calibration gas by which there is a precisely composed concentration of detectable gas exposed towards the gas detector or gas analyser. SEMA Gases delivers multiple types of calibration gases suitable for the shipping industry, offshore industry, chemical industry, laboratories, and universities.

Regulators are used to ensuring you receive the required flow of calibration gas for your application. We only provide a variety quality gas regulators directly available from stock.

We have a variety of accessories that make your work much safer. Think of accessories as carrying cases, gas sampling bags, sampling hoses and different types of calibration adaptors. All of our accessories are made of the best quality available and developed by renown brands such as Riken Keiki, Dräger, MSA, Crowcon and SGI.

Gas detectors are instruments which detect the attendance of gases in an area or room. This area or room could be for example in confined spaces of ships. A gas detector comes in two different variants. Variant one could be a portable gas detector which a person carries with him for personal safety. Variation two could be a fixed gas detection system which controls the security of an area or a confined space. Gas detectors are used to detect combustible gases, toxic gases and oxygen. When an unsafe condition occurs due to a gas leak, the gas sensor will provide a sounding alarm, a visual alarm and readable alarm on the display. These signals will give a user or persons the warning of the presence of an unsafe situation. This notification opens up the opportunity to leave the dangerous area or confined space.

Gas detectors are most commonly used in the industry, shipping, offshore, (petro) chemical industry, firefighting, etc. But with buying a detector alone, you are not quite there yet. Gas detectors need to be calibrated and certified according to international regulations, before a given time.