As recycling becomes more common, use of landfill is reducing, but it is still an important means of waste disposal. For example, 2012-13 figures from Defra (department of the environment, food and rural affairs) for England show that 8.51 million tonnes, or 33.9%, of waste collected by local authorities went to landfill.
After last week’s comparative levity, this week, I am discussing something rather more serious.
When it comes to detecting hydrocarbons, we often don’t have a cylinder of target gas available to perform a straight calibration, so we use a surrogate gas and cross calibrate. This is a problem because pellistor’s give relative responses to different flammable gases at different levels. Hence, with a small molecule gas like methane a pellistor is more sensitive and gives a higher reading than a heavy hydrocarbon like kerosene.