Search results
Results From The WOW.Com Content Network
A DID is an ion detector which uses a high-voltage electric discharge to produce ions. The detector uses an electrical discharge in helium to generate high energy UV photons and metastable helium which ionizes all compounds except helium. [1] The ions produce an electric current, which is the signal output of the detector. The greater the ...
Fault detection, isolation, and recovery (FDIR) is a subfield of control engineering which concerns itself with monitoring a system, identifying when a fault has occurred, and pinpointing the type of fault and its location. Two approaches can be distinguished: A direct pattern recognition of sensor readings that indicate a fault and an analysis ...
Schematic of a flame ionization detector for gas chromatography. A flame ionization detector (FID) is a scientific instrument that measures analytes in a gas stream. It is frequently used as a detector in gas chromatography. The measurement of ions per unit time makes this a mass sensitive instrument. [1]
The specificity of the test is equal to 1 minus the false positive rate. In statistical hypothesis testing, this fraction is given the Greek letter α, and 1 − α is defined as the specificity of the test. Increasing the specificity of the test lowers the probability of type I errors, but may raise the probability of type II errors (false ...
A chromatography detector is a device that detects and quantifies separated compounds as they elute from the chromatographic column.These detectors are integral to various chromatographic techniques, such as gas chromatography, [1] liquid chromatography, and high-performance liquid chromatography, [2] and supercritical fluid chromatography [3] among others.
The detection limit for electron capture detectors is 5 femtograms per second (fg/s) and the detector commonly exhibits a 10,000-fold linear range. [ citation needed ] This made it possible to detect halogenated compounds such as pesticides and CFCs , even at levels of only one part per trillion ( ppt ), thus revolutionizing our understanding ...
ELSDs analyze solutes eluting out of the chromatographic column, both in LC and SFC. As the eluent exits the column's outlet into the detector inlet, it is mixed with an inert carrier gas (usually nitrogen) and forced through a nebulizer, which separates the liquid into fine aerosolized droplets. These droplets then pass into a heated drift ...
Schematic of a solid-state detector. The operating principle of Semiconductor detectors is similar to gas ionization detectors: except that instead of ionization of gas atoms, free electrons and holes are produced which create a signal at the electrodes. The advantage of solid state detectors is the greater resolution of the resultant energy ...