Self-Calibrating Instrument Using GPS-Traceable Reference Signals
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
Existing measurement instruments require frequent recalibration at standards laboratories, which leads to instrument downtime and inefficiency, as they need to be certified to international standards, often using in-house standards that require periodic adjustment or generation.
Innovation Solution
The development of self-calibrating instruments that produce a reference time or frequency signal traceable to international standards, allowing for in situ calibration using GPS signals, local oscillators, and transducers like Josephson junction arrays, enabling calibration of ADCs and DACs without removing the instrument from service.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Measurement precision
If instruments are calibrated using in-house standards at standards laboratories, then measurement accuracy is maintained, but instrument downtime increases and calibration frequency must be high
Solution Approach 1:
The instrument performs self-calibration by generating its own reference signals using onboard time/frequency standards (GPS receiver, local oscillators, Josephson junction arrays) rather than requiring external calibration services. The calibration module uses these self-generated reference signals to adjust measurement results, enabling the instrument to calibrate itself while in service without needing to be transported to standards laboratories.
Solution Approach 2:
The instrument integrates multiple functions including time/frequency generation, reference signal generation, measurement, and calibration within a single system. The time/frequency generation unit serves dual purposes: providing timing for operations and generating reference signals for calibration, eliminating the need for separate calibration equipment and reducing downtime.
2Measurement precision
If instruments are frequently recalibrated at standards laboratories, then measurement accuracy is maintained, but productivity decreases
Solution Approach 1:
The instrument performs self-calibration autonomously using its integrated time/frequency generation unit and calibration module. This eliminates the need to remove the instrument from service for external calibration, maintaining continuous operation and high productivity while ensuring measurement accuracy through regular self-calibration cycles.
Solution Approach 2:
The self-calibration capability allows the instrument to maintain continuous operation without interruption for external calibration. The calibration process occurs in-situ during normal operation, ensuring the instrument remains productive while maintaining measurement accuracy through ongoing calibration.
3Reliability
If in-house standards are adjusted periodically to international standards, then traceability is maintained, but device complexity increases
Solution Approach 1:
The GPS receiver serves as an intermediary that provides access to international time/frequency standards through satellite signals. This external reference source disciplines the local oscillators and Josephson junction arrays, ensuring traceability to international standards without requiring complex internal standard maintenance or periodic adjustments at standards laboratories.
Solution Approach 2:
The system replaces mechanical/physical standards (in-house voltage and frequency standards requiring periodic adjustment) with electronic/time-based standards using GPS-synchronized oscillators and Josephson junction arrays. This substitution simplifies the calibration system by using time/frequency references that are inherently more stable and easier to maintain traceability through electronic synchronization rather than physical standard adjustments.
Applied Scientific Principles
This section explains which scientific principles are used to turn an abstract innovation direction into a practical engineering solution.
Function Achieved in This Case
Enables in situ calibration with minimal downtime, ensuring measurement accuracy by using traceable reference signals to adjust output signals and measurement results, thus reducing the need for frequent laboratory recalibrations.
Implementation Method 1
The GPS receiver (4) receives GPS signals
Implementation Method 2
the time/frequency comparator and servo system (8) compares the reference time/frequency with an output signal from the local time/frequency generator (10) to produce a correction signal
Implementation Method 3
The Josephson junction array (12) converts the reference time/frequency to a highly reproducible reference voltage
Data Source
AI summary
An instrument including a device, a transducer and a calibration module is disclosed. The device produces a reference time and/or a reference frequency. The transducer converts the reference time and/or the reference frequency to a reference signal. The calibration module adjusts an output signal generated by the instrument and/or a result of a measurement taken by the instrument, based on the reference signal. A system including the instrument and a method of calibrating the instrument are also disclosed.