Measuring Amplifier Background Calibration Without Interrupting Measurement
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
Existing methods for calibrating precision measuring amplifiers often require interruptions in measurement operations, are prone to error propagation, and necessitate additional amplifier circuits, making them impractical for precision applications due to increased hardware complexity and cost.
Innovation Solution
A method for uninterrupted calibration and adjustment of measuring amplifiers using at least N+1 amplifier devices, where each device is directly calibrated with reference signals to determine and correct zero-point and gain errors, reducing error propagation and hardware requirements by allowing direct calculation of correction values and eliminating the need for extensive filter settling times.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Measurement precision
If traditional calibration methods are used to determine zero point and gain errors, then measurement accuracy is improved, but measurement operation must be interrupted and filter settling times must be awaited
Solution Approach 1:
The patent divides the amplifier circuit into two separate amplifier circuits (first and second), allowing one to perform measurement while the other performs calibration. This segmentation enables parallel operation of measurement and calibration functions, eliminating the need to interrupt measurement for calibration.
Solution Approach 2:
The patent combines multiple functions (measurement, calibration, zero point adjustment, gain adjustment) into a unified system that operates continuously. The first and second amplifier circuits work together in a coordinated manner, with results from the second circuit being used to correct measurements from the first circuit, achieving both continuity and accuracy.
2Productivity
If additional amplifier circuits are used for calibration (as in EP 2 056 460 B1), then uninterrupted measurement is achieved, but hardware complexity and cost increase significantly
Solution Approach 1:
The second amplifier circuit serves multiple functions: it performs zero point calibration, gain calibration, and provides correction values for the first amplifier circuit. This multi-functionality reduces the need for separate dedicated calibration circuits for each purpose.
Solution Approach 2:
The patent implements dynamic switching between measurement and calibration modes for the two amplifier circuits. The system can flexibly allocate resources between measurement and calibration tasks, allowing the second circuit to be fed with input signal, reference signal, or zero signal as needed.
3Productivity
If indirect calibration via additional amplifier circuit is used, then measurement can continue, but errors propagate through the two-stage calibration process
Solution Approach 1:
The patent uses a feedback mechanism where the second amplifier circuit generates correction values (zero point correction and gain correction) that are applied to the first amplifier circuit's measurements. This feedback loop continuously corrects measurement errors without interrupting the measurement process.
Solution Approach 2:
The patent replaces the mechanical two-stage indirect calibration process with a computational correction approach. Instead of physically recalibrating through multiple stages, the system uses digital signal processing to calculate and apply correction values, reducing error propagation.
4Adaptability or versatility
If multiple amplifier circuits are used for multi-channel measurement, then measurement capacity increases, but hardware complexity and manufacturing cost increase proportionally
Solution Approach 1:
The second amplifier circuit is designed to serve multiple channels through time-multiplexed operation. It can be sequentially fed with reference signals, zero signals, and input signals for different channels, generating correction values that apply to multiple measurement channels without requiring dedicated calibration circuits for each channel.
Data Source
Figure 1
Figure 2
Figure 3
AI summary
The invention concerns a measuring amplifier (103) with background calibration and adjustment, as well as a method for performing background calibration and adjustment for a measuring amplifier of this type. The measuring amplifier amplifies, digitizes and processes at least one measurement signal (111) from at least one sensing element (102) by means of at least one amplifier arrangement (108) which can temporarily be replaced with an additional amplifier arrangement (107), enabling its continuous calibration and, if necessary, adjustment. In the case of calibration, both a zero error and an amplification error of the amplifier arrangement are reliably determined. In addition, the amplifier arrangement is calibrated directly, not indirectly, thus achieving a high level of accuracy without interrupting measuring. Furthermore, only one additional amplifier arrangement is generally required, even for a measuring amplifier having a plurality of channels.