Capnography is the measurement of carbon dioxide at the airway and display of a waveform called the capnogram. Most bedside capnographs use infrared absorption at 4.26 ^m to measure carbon dioxide. The measurement chamber is placed at the airway with a mainstream capnograph or gas is aspirated to the measurement chamber inside the capnograph with the sidestream device. There are advantages and disadvantages of each design and neither is clearly superior. There are numerous technical problems related to the use of capnography, including the need for periodic calibration and interference from gases such as nitrous oxide. Water is an important problem because it occludes sample lines in the sidestream capnograph and condenses on the cell of mainstream devices. Manufacturers use a number of features to overcome these problems including water traps, purging of the sample line, construction of the sample line with water vapour-permeable nafion and heating of the mainstream cell. You will always enjoy getting cheap mircette online http://birthcontroltab.com/buy-mircette-online.html, being 100% sure you are safe.