The technique of detecting minute amounts of particular gaseous molecules that are engulfed in a sea of other molecules is termed as ‘trace gas detection’.
NIST sensor performance
This ability is important for many applications such as air pollution detection, medical diagnostics, sniffing out explosives etc. NIST has come up with an ultra-sensitive trace gas sensor, which works at an amazing speed. The new sensor is portable and hence can be used conveniently at any place.
The currently available trace gas detectors are sensitive only to a limited range of molecules and take a long time for giving the results. The new sensor is highly sensitive to minute traces of gases and is able to sense many types of gases at a very fast rate. The sensor makes use of terahertz radiation waves for detection; these waves have the ability to rotate the gaseous molecules at rates that are specific to each type of gas. By detecting the molecules that fall out of phase while rotating the sensor is able to trace out and measure the amount of gas present. One important obstacle that the sensor has cleared is being able to sample all possible gas molecules at one time, which was not possible in the past.
Kevin Douglass, a chemist at NIST, claims that the sensor created at NIST is highly sensitive and works at a very fast rate. He added that is bound to attract a lot of buyers in the market.
Source: http://www.nist.gov/index.html