Vetus GD1000 Manual De Instalación Y Usuario página 16

2 Introduction
The VETUS gas detector together with one or two sensors forms a gas detection system with
two different functions.
In the first place to detect a range of combustible gases *) to prevent the risk of explosion on
board.
Secondly to detect the poisonous gas carbon monoxide (CO) **) to prevent the formation of a
dangerous and poisonous atmosphere for people.
The danger formed by carbon monoxide is dependent on a time-weighted average. This
means that it is dependent on both the concentration of carbon monoxide and the time that
the carbon monoxide is present.
The concentration of carbon monoxide therefore has influence on the time before the gas
detector gives an alarm.
Both detector functions are carried out at the same time.
Combustible gases and vapours should not or only in extremely small amounts be pre-
*)
sent in the normal surrounding atmosphere.
Combustible gases are e.g. propane, butane, methane and hydrogen. About 81 % of the
composition of natural gas is methane.
**) Carbon monoxide (chemical formula CO) is an invisible, colourless and odourless gas. It
is formed by incomplete combustion in equipment burning organic fuels such as oil, gas,
petrol, coal and wood (so not in electrical installations!). Incomplete combustion means
that there is insufficient oxygen present to allow good or complete combustion.
When carbon monoxide is breathed in it is taken up by the blood via the lungs and
attaches itself to the red blood cells. Red blood cells transport oxygen through the body.
Because carbon monoxide attaches to red blood cells about 200x more easily than oxy-
gen it can very easily displace oxygen from the blood and this can therefore transport less
oxygen.
The gas detector can be connected to a 12 Volt or a 24 Volt direct current power supply.
The gas detector can be used in either continuous or intermittent mode according to choice,
see 3.2.
It is recommended that a check for the presence of gas should
when the ship is not in use!
Therefore, always keep the power supply to the gas detector switched on
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be made, even
always
Gasdetector GD1000