US 5,459,677 A · Calibration transfer for analytical instruments

Abstract

A technique for transferring a multivariant calibration model from a reference analytical instrument to a target analytical instrument that may be a different instrument, or the same instrument at a later time. In a "direct" approach, a plurality of transfer samples are selected, and a plurality of measurements are made for each transfer sample using the reference instrument, producing a reference instrument response for each sample. These measurements are repeated for the target instrument, to produce a target instrument response for each transfer sample. One then generates transfer coefficients capable of performing a multivariate estimation of the reference instrument responses for the transfer samples from the target instrument responses for those samples. The transfer coefficients may then be used to convert a target instrument response for an unknown sample into the equivalent response for the reference instrument. In an important "piecewise" variation, the transfer coefficients comprise a plurality of estimation coefficients for estimating each reference data value from more-than-one but less-than-all target data values. "Classical" and "inverse" transfer techniques are also described, wherein target instrument responses for the transfer samples are combined with reference instrument responses for the full set of calibration samples, to derive a multivariate prediction model for the target instrument.

Claims18

Dependent claims

A method of producing a multivariate prediction model for predicting a property of a sample using a target spectrometer, based in part upon data measured by a reference spectrometer, the method comprising:

producing property data by measuring said property for each of a plurality of calibration samples;
for each calibration sample, producing a reference spectrometer response by making a plurality of measurements using the reference spectrometer;
for each transfer sample in a subset of the calibration samples, producing a target spectrometer response by making a plurality of measurements using the target spectrometer;
using the reference spectrometer responses for the calibration samples, the target spectrometer responses for the transfer samples, and the property data, producing estimates of the responses of the target spectrometer to the calibration samples;
and
producing a multivariate prediction model for the target spectrometer by combining the estimates of the responses of the target spectrometer to the calibration samples with the property data.

3 more elements

producing property data by measuring said property for each of a plurality of calibration samples;
for each calibration sample, producing a reference spectrometer response making a plurality of measurements using the reference spectrometer;
for each transfer sample in a subset of the calibration samples, producing a target spectrometer response by making a plurality of measurements using the target spectrometer;
producing a multivariate prediction model for the reference spectrometer by using the reference spectrometer responses for the calibration samples the property data;
and
using the reference spectrometer responses for the transfer samples, the target spectrometer responses for the transfer samples, the multivariate prediction model for the reference spectrometer, and the property data, producing a multivariate prediction model for the target spectrometer.

3 more elements

A method of using a target spectrometer to perform a plurality of measurements on an unknown sample so as to produce an estimate of a reference spectrometer response for the unknown sample, the reference spectrometer response comprising values that would have been obtained by performing said plurality of measurements on the unknown sample using a reference spectrometer, the method comprising:

providing a plurality of transfer samples;
producing a reference spectrometer response for each transfer sample, by making a plurality of measurements using the reference spectrometer;
producing a target spectrometer response for each transfer sample, by making a plurality of measurements using the target spectrometer;
producing transfer coefficients for performing a multivariate estimation of the reference spectrometer responses for the transfer samples from the target spectrometer responses for the transfer samples;
producing a target spectrometer response for the unknown sample, by making a plurality of measurements using the target spectrometer;
and
converting the target spectrometer response for the unknown sample into an estimate of the reference spectrometer response for the unknown sample, using the transfer coefficients.

4 more elements

Dependencies are inferred from the claim text.

Calibration transfer for analytical instruments

Life of this patent

Calibration transfer for analytical instruments

Life of this patent

Abstract

Claims18