US 4,056,725 A · Method of and system for compensating the distortion of amplitude spectra of multichannel analyzers in spectrometry

Abstract

Pulses from a particle detector and a reference-pulse generator are fed to multichannel analyzer converting the pulse amplitudes into binary signals appearing on its stage outputs, certain of these stage outputs being connected to a pair of decoders in such a way that one decoder responds to pulse amplitudes in a first group of n channels whereas the other decoder registers amplitudes in a second n-channel group divided into two halves which bracket the first group. The reference pulses are of such amplitude as to fall in the middle of the first channel group; if a measuring pulse in the detector output coincides with a reference pulse, the amplitude of the latter is either increased or decreased so as to fall mainly in one or the other half of the second group. A logic network controlled by the pulse generator energizes a forward-stepping or a backward-stepping input of a reversible pulse counter from the output of the first or the second decoder, respectively, according to whether a reference pulse occurs alone or is accompanied by a measuring pulse. When the counter reaches the limit of its counting capacity, the analyzer is cut off. The times required to attain a full count are compared for a standard sample and a test sample.

Claims10

Dependent claims

A method of compensating pulse-amplitude distortion in a spectrometric operation in which a measuring pulse due to particle emission from a sample is converted in a multichannel analyzer into a digital signal identifying one of a multiplicity of channels corresponding to a respective pulse amplitude, comprising the steps of:

generating a train of reference pulses of stable frequency and of an amplitude falling within a first group of said channels;
concurrently feeding said reference pulses and measuring pulses to said multichannel analyzer for identifying, upon a coincidence of a reference pulse with a measuring pulse, a channel within a second group of said channels corresponding to the combined amplitude of the coincident pulses;
and
determining, from the occurences of identification of channels in said first and second groups, the ratio of reference-pulse rate to measuring-pulse rate for a standard sample and a test sample to be compared therewith.

1 more element

A system for compensating pulse-amplitude distortion in a spectrometric operation in which a pulse due to particle emission from a sample is converted into a digital signal identifying one of a multiplicity of channels corresponding to a respective pulse amplitude, comprising:

detector means for generating measuring pulses in response to the flow of particles from a sample to be measured;
a generator of reference pulses of predetermined frequency and amplitude;
a multichannel analyzer converting the amplitudes of incoming pulses into digital codes identifying a multiplicity of channels, said analyzer having a pulse-receiving input and a set of stage outputs carrying said digital codes, said detector means and said generator having outputs connected to said pulse-receiving input;
a first decoder connected to certain of said stage outputs for emitting a first counting pulse in response to a pulse amplitude in said pulse-receiving input falling within a predetermined first group of said channels encompassing the amplitude of said reference pulses;
a second decoder connected to other of said stage outputs for emitting a second counting pulse in response to a pulse amplitude in said pulse-receiving input falling within a predetermined second group of said channels adjoining said first group;
a reversible pulse counter having a forward-stepping input connected to said first decoder and a backward-stepping input connected to said second decoder for respectively receiving said first and second counting pulses therefrom;
and
gating means controlled by said generator and interposed between said decoders and said pulse counter for allowing the transmission of a counting pulse only within a limited period following the generation of any reference pulse.

5 more elements

Dependencies are inferred from the claim text.

Method of and system for compensating the distortion of amplitude spectra of multichannel analyzers in spectrometry

Life of this patent

Method of and system for compensating the distortion of amplitude spectra of multichannel analyzers in spectrometry

Life of this patent

Abstract

Claims10