Glossary of terms used on this site

A highly toxic, flammable, pale yellow gas with a sharp pungent smell. Chlorine attacks the respiratory system, eyes and skin. Denser than air, it tends to accumulate at the bottom of poorly verntilated spaces. Chlorine gas is a strong oxidizer, making it an essential compound in many industries. Chlorine is detectable with colorimetric detection tubes and dedicated electrochemical cells.

Glass tubes through which a gas sample is drawn to allow the user to measure various types of gas found in the atmosphere. The tubes contain reagents that filter or bond to non-target gases and reagents that change hue when they come in contact with their target gas. The concentration is given by the length of the color change, as indicated by a printed scale on the outside of the glass tube.

A gas that is held under greater than atmospheric pressure.

Generally defined as an enclosed or partially enclosed environment, with or without restricted access, not designed for the stay of persons. They generally offer limited freedom of movement, limited accessibility and limited escape routes. Confined spaces are generally poorly ventilated and are susceptible to the accumulation of toxic, flammable, asphyxiant or otherwise hazardous compounds. Laws, regulations and best practices demand the confined space to be tested for various hazards before persons may enter, sometimes under the condition of further personal protection equipment. Gas detectors, often fitted with a pump, probe, a length of hose and ball floats, are used to check confined spaces for the presence of oxygen, combustibles and toxic compounds. Also, when working in a confined space, gas detection equipment is used to alarm workers of deteriorating conditions.

An exchange during which a client and an expert engage in a process to find the best solutions for a problem held by the client. 7Solutions is an independent supplier. We work with all manufacturers and we know the market like the back of our hand. Which means we can provide you with the exact quality and characteristics, even the exact brand, you are looking for. Whether you require the technologically advanced or the dependable work horse. Knowing the market like we do enables us to give great advice of which instrument is suitable for any given set of circumstances.

In fixed gas detection, a device to monitor multiple sensors at once and switching alarms or processes as programmed.

Term describing a substance

More precisely, the volumetric mass density, also known as specific mass, of a substance is the mass of a unit volume of that substance.

In gas detection, the lowest dectable concentration.

A component of a gas detector that is capable of generating electrical energy from chemical reactions or causing chemical reactions by adding electrical energy, generating a potential difference from which a concentration value can be calculated.

An explosion is a rapid increase in volume and release of energy in an extreme manner, usually with the generation of high temperatures and the release of gases. Usually, an area designated as susceptible to explosion danger is one where two of the three requirements for a combustive explosion are or can be present: a combustible material, an oxydizer and a source of ignition. Areas classified into zones (0, 1 and 2 for gases, vapours and mist or zone 20, 21 and 22 for flammable dust) must be protected from effective sources of ignition. Zone 0 and 20 represent the highest risk. The intrinsic safety certificate of a piece of equipment classifies it for use in certain zones, depending on how likely it is to act as a source of ignition. Areas classified as zone 0 or 20 require category 1 equipment; zones 1 and 21 category 2; while zone 2 and 22 require category 3 equipment.

The highest and lowest concentrations at which a given gas can ignite while mixed with air at 25

Or occupational exposure limit, an upper limit on the acceptable concentration of a hazardous substance in workplace air for a particular material or class of materials. Exposure limits are usually set and enforced by national authorities, although sometimes they are merely recommended. Many means are available to companies to restrict the risks associated with the substances present at its premises, of which gas detection is certainly a very important component, both in the risk assessment stage and in the enforcement stage.

Scale for measuring temperature that originated with Daniel Gabriel Fahrenheit in the 1700s. Defined by the temperature at which water freezes (32

Any situation in which a risk of fire is present, whether that pertains to the presence of combustible substances, a ready source of ignition or of elevated concentrations of oxydizers.

See Stationary Gas Detection.

Flame detection works through IR, near-IR, UV analysis or similar techniques, thermal imaging and/or image recognition, through ionization detection or with thermocouple sensors. Flame detectors are used for fire alarms, process control, and cooking and heating systemes.

A gas is classified as extremely flammable if it is ignitable when in a mixture of 13% or less by volume in air at 20

The lowest temperature at which the vapours of a volatile substance ignite when given an ignition source.

An electrochemical cell that converts the chemical energy of a fuel and an oxidizing agent into electricity through a pair of redox reactions. In gas detection, carbon monoxide and alcohol sensors (for breathalyzers) can be made using the fuel cell principle.