Dual Amplifier Drift Correction for Continuous Signal Measurement
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Solution Overview
Problem
Existing measuring amplifiers face challenges in maintaining continuous measurement of input signals due to drift errors caused by component tolerances and aging, which disrupts uninterrupted signal processing and control tasks.
Innovation Solution
A measuring amplifier arrangement with two analog amplifier circuits, one continuously measuring the input signal and the other switching between the input signal, a reference signal, and a zero signal, allows for continuous correction of drift errors by determining and applying correction values using a microprocessor and analog/digital converters, ensuring uninterrupted measurement.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Measurement precision
If dual-slope converters or switching between measurement signal and calibration signal are used to compensate for drift behavior, then measurement accuracy is improved, but continuous measurement is interrupted
Solution Approach 1:
The measuring amplifier is divided into two separate amplifier circuits: a first amplifier circuit that continuously measures the input signal, and a second amplifier circuit that periodically measures reference signals (zero signal and reference signal) to determine drift errors. This segmentation allows continuous measurement while separately performing drift compensation without interrupting the main measurement stream.
Solution Approach 2:
The second amplifier circuit acts as an intermediary that periodically measures drift errors using reference signals. The drift errors determined by this intermediary circuit are then used to correct the measurements from the first amplifier circuit, enabling continuous measurement with periodic correction.
2Measurement precision
If measurement amplifier input is switched between measurement signal and internal calibration signal to determine drift influences, then drift correction is achieved, but uninterrupted control is not possible
Solution Approach 1:
The system segments the measurement function into two parallel amplifier circuits operating simultaneously. The first circuit maintains uninterrupted measurement for control tasks, while the second circuit periodically determines drift errors using reference signals, enabling both continuous productivity and drift correction.
Solution Approach 2:
The first amplifier circuit continuously measures the input signal without interruption, maintaining uninterrupted control capability. The drift correction from the second circuit is applied continuously to the measured values, ensuring both continuous operation and accurate drift compensation.
3Measurement precision
If integrated analog-to-digital converter methods with downstream digital filters are used, then signal processing is improved, but continuous measurement requirement cannot be met due to drift determination interruptions
Solution Approach 1:
The system separates the continuous signal processing function (first amplifier circuit with ADC and digital filter) from the periodic drift determination function (second amplifier circuit). This allows the integrated ADC and digital filter to operate continuously on the main measurement signal while drift correction is periodically applied without interrupting the signal processing chain.
Data Source
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AI summary
The method involves continuously measuring an input signal (3) and converting the input signal into measuring values by an analog amplifier circuit (1). Measuring values of another analog amplifier circuit (2) are corrected based on a reference signal (5) and a zero signal (7) i.e. internal zero signal. Correction values for the measuring values of the former circuit are determined by a microprocessor (10) from the comparison of the measuring values of the former circuit and the corrected measuring values of the latter amplifier circuit. The circuits are provided as voltage amplifiers. An independent claim is also included for an arrangement for correcting input signals of a measuring amplifier.