Green House Gases

Global Warming

The earth is warmed by the sun. Over time, the amount of energy transmitted to the earth’s surface is equal to the amount of energy radiated back into space in the form of infra-red radiation, while the temperature of the earth stays virtually constant. However, the temperature of the earth is strongly influenced by the composition of the earth’s atmosphere. Many gases in the atmosphere absorb infra-red radiation and participate in the "natural greenhouse effect", trapping the heat from the sun and lifting the average temperature of the earth. (see Table below).

Measuring Greenhouse Gases

The most important greenhouse gases are Water Vapour, Carbon Dioxide, Methane and Nitrous Oxide. Usually, measuring long-term average values is considered adequate, but taking into account the fairly big changes (see table left), that take place in the interchange between the natural sources and sinks in the atmosphere, it has been shown that to study these phenomena properly a measuring instrument which has a response time of a few minutes is very beneficial.

The Solution

Using the Photoacoustic Field Gas-Monitor 1412 makes it possible to measure the gases quickly and accurately. The graph to the right shows the recorded concentrations over a period of a week. Using the software, which is included with the monitor, it is possible to zoom in on a single sample, giving a true time relationship for up to five gases plus water vapor.