Katharometer

related topics
{acid, form, water}
{math, energy, light}
{system, computer, user}
{rate, high, increase}
{work, book, publish}

A katharometer is a thermal conductivity device for determining one gas in a binary or pseudo-binary mixture. The thermal conductivity of a gas is inversely related to its molecular weight[1]. Hydrogen has approximately six times the conductivity of nitrogen for example.

Contents

Process description

It functions by having two parallel tubes both containing gas and heating coils. The gases are examined by comparing the rate of loss of heat from the heating coils into the gas. The coils are arranged in a bridge circuit so that resistance changes due to unequal cooling can be measured. One channel normally holds a reference gas and the mixture to be tested is passed through the other channel.

Applications

In the oil industry katharometers have been used for a long time for hydrocarbon detection but have a history of unstable calibrations in non stationary oil related applications. In normal drilling practice, 5 hydrocarbon gases, plus a couple of non-hydrocarbon gases, are expected in normal samples resulting in cross-talk between the methane absorption line and the ethane. Hence the current use of flame ionization detectors.

Katharometers are used medically in lung function testing equipment and in gas chromatography. The results are slower to obtain compared to a mass spectrometer, but the device is inexpensive, and has good accuracy when the gases in question are known, and it is only the proportion that must be determined.

Monitoring of hydrogen purity in hydrogen-cooled turbogenerators.

See also

References

External links

Full article ▸

related documents
Octahedrite
Ununennium
Allene
Surfactant
Potassium ferrocyanide
Uraninite
List of synthetic polymers
Thermal diffusivity
Johannes Nicolaus Brønsted
Calamine (mineral)
Hypoxanthine
Isoleucine
Phenyl group
Perlite
Coenzyme A
Physical chemistry
Ulexite
Putrescine
Periodic table (standard)
Vitamin E
Genetic material
Chemisorption
Ketene
Anatase
Cobalt bomb
Ornithine
Weatherization
Leucine
HMX
Valine