Apparatus and method for providing corrected normalized signals corresponding to the composition of a material

Claim 2

Apparatus for providing corrected normalized signals corresponding to the composition of a material, comprising chromatograph means sampling the material and providing a first signal and a pulse signal, each pulse in the pulse signal coinciding with a different peak amplitude occurring in the first signal, means controlled by the pulse signal for providing a plurality of voltages, each voltage corresponding in amplitude to a different peak amplitude of the first signal, means receiving the first signal and the pulse signal from the chromatograph means and the plurality of voltages from the voltage means for providing correction signals, means responsive to the pulse signal from the chromatograph means for sampling and holding each peak of the first signal from the chromatograph means, means connected to the sample and hold means and to the correction signal means for multiplying each held peak voltage with a corresponding correction signal to provide corrected peak voltages, and means connected to the multiplier means for normalizing each corrected peak voltage to provide corrected normalized signals.

Claim 3

Apparatus as described in claim 1 in which the correction signal means includes means responsive to the pulse signal from the chromatograph means and receiving the first signal from the chromatograph means for providing a plurality of signals, each signal corresponding to the area of a different peak in the first signal, and means connected to the sample and hold means, to the peak area signal means and to the multiplier means for dividing each held peak voltage from the sample and hold meanS with a corresponding peak area signal to provide the correction signals.

Claim 4

Apparatus as described in claim 2 in which the peak area signal means includes means connected to the chromatograph means for providing a plurality of signals, each signal corresponding to the area under the curve for a different peak of the first signal from the chromatograph means, occurring means connected to the chromatograph means for determining an average baseline for each peak of the first signal and providing corresponding signals, means connected to the baseline signal means for determining the area under each baseline and providing signals corresponding thereto, and means connected to the area under the curve signal means for subtracting each baseline area signal from a corresponding area under the curve signal to provide the signals corresponding to the peak areas.

Claim 5

Apparatus as described in claim 3 in which the area under the curve signal means includes a slope detector receiving the first signal from the chromatograph means and providing a first pulse at the start of each peak and a second pulse at the end of each peak in the first signal, a voltage to frequency converter receiving the first signal from the chromatograph means and providing a pulse signal having a frequency corresponding to the amplitude of the first signal from the chromatograph means, counting means, switching means connected to the slope detector and to the voltage to frequency converter and controlled by the pulses from the slope detector to pass the pulse signal from the voltage to frequency converter to the counting means between each first and second pulses from the slope detector so that each count in the counting means corresponds to the area under the curve for a different peak of the first signal from the chromatograph means, means connected to the counting means for providing the signals corresponding to the area under the curve for each peak in the first signal in accordance with the counts in the counting means; and the baseline signal means includes second sample and hold means for sampling the first signal from the chromatograph means at the start of each peak and at the end of each peak of the first signal, means connected to the second sample and hold means for providing a signal corresponding to the average baseline in accordance with the held portions of the first signal from the second sample and hold means, a second voltage to frequency converter providing the pulse signal having a frequency corresponding to the amplitude of the voltage baseline signal, second counting means, means controlled by the pulses from the slope detector to provide signals corresponding to the time base of each peak of the first signal provided by the chromatograph means, switching means controlled by the time base signals from the time base signal means for controlling the counting by the counting means of the pulses in the pulse signal from the second voltage to frequency converter so that each count in a second counting means corresponds to an area under a different baseline, and means connected to the second counting means for providing the signals corresponding to the baseline area in accordance with the counts contained in the second counting means.

Claim 8

A method as described in claim 5 in which the providing correction signal step includes providing a plurality of signals, each signal corresponding to the area of a different peak in the first signal, and dividing each held peak voltage with a corresponding peak area signal to provide a correction signal.

Claim 9

A method as described in claim 6 in which the providing peak area signal step includes providing a plurality of signals, each signal of said second plurality corresponding to the area under the curve of the first signal for a different peak of the first signal, determining the voltage baseline for each peak of the first signal, providing a signal corresponding to each average baseline, determining the area under each baseline in accordance with the baseline signals, providing signals corresponding to the areas under the baselines and subtracting each baseline area from a corresponding area under the curve to provide a signal corresponding to the peak area.

Claim 10

A method as described in claim 7 in which the providing area under the curve signal step includes providing the first pulse at the start of each peak in the first signal and a second pulse at the end of each peak, providing a first pulse signal having a frequency corresponding to the amplitude of the first signal, connecting the pulses in the first pulse signal between each first pulse and each second pulse so that each count corresponds to the area under the curve for a different peak of the first signal, providing the signals corresponding to the areas under the curve for each peak in accordance with the counts; and the providing the baseline signals steps including sampling and holding the first signal at the start of each peak and at the end of each peak of the first signal, providing a signal corresponding to the average baseline in accordance with the last mentioned held portions of the first signal, providing a second pulse signal having a frequency corresponding to the amplitude of the average pulse line signal, counting the pulses in the second pulse signal during those portions of the second pulse signal associated with the peaks of the first signal so that each count of the second counting corresponds to an area under a different baseline and providing signals corresponding to the baseline areas in accordance with the counts of the last mentioned counting step.