Apparatus for quantifying an element by means of laser induced fluorescence in a high frequency plasma

摘要

The device consists of a plasma torch (10 - 14) for creating an HF plasma (16) in an airtight vessel (2). A sample (6) containing an element to be quantified is injected into the plasma. A laser (18) emits pulses of wavelength and spectral width capable of exciting the element. Prisms (22, 24) send the laser pulses into the plasma so that the element will emit light pulses by fluorescence. A lens (46) focuses the region of the plasma (36) excited by the laser onto a spectrometer (42), which selects the pulses emitted by the element and transforms them into an electrical signal. An electronic circuit (48, 50) processes the electrical signal from the spectrometer in synchronism with the laser pulses. Means are provided (52) for determining the quantity of the element contained in the sample from the processed electrical signal. IMAGE