High Resolution Temperature Measurement Using Segmented Time
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Solution Overview
Problem
Existing temperature measurement systems face challenges in achieving high resolution and high sampling rates while maintaining low power consumption, which is essential for applications like industrial process control, biological sensing, and battery-powered devices that require long-term operation.
Innovation Solution
The method involves coupling coarse and fine time measurements with a digital processor to determine high resolution temperature using a resistive temperature sensor, where the fine time measurement is enhanced by a charge time measurement unit (CTMU) and an analog-to-digital converter, allowing for precise timing and increased resolution without significantly increasing power consumption.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Measurement precision
If Delta-Sigma ADC is used for high resolution temperature measurement, then measurement precision is improved, but sampling rate is limited to less than 500 Hz and power consumption increases
Solution Approach 1:
The patent segments the temperature measurement process into two distinct phases: a coarse measurement phase that captures general temperature trends at higher sampling rates, and a fine measurement phase that provides high-resolution data at lower sampling rates. This segmentation allows the system to achieve both high precision when needed and high sampling rates when temperature changes are rapid, resolving the contradiction between measurement precision and productivity.
2Measurement precision
If Delta-Sigma ADC is used for high resolution temperature measurement, then measurement precision is improved, but power consumption increases
Solution Approach 1:
The patent implements periodic action by alternating between coarse and fine measurement modes based on temperature stability detection. The system performs coarse measurements continuously, then periodically initiates fine measurements only when temperature stabilizes within a threshold. This periodic switching reduces overall power consumption compared to continuous high-resolution measurement, while still achieving high precision when temperature conditions warrant it.
3Measurement precision
If counter clock rate is increased to enhance temperature measurement resolution, then measurement precision is improved, but power consumption increases
Solution Approach 1:
The patent applies dynamics by making the measurement resolution adaptive rather than fixed. The system dynamically adjusts between coarse and fine measurement modes based on real-time temperature stability assessment. When temperature is stable, the system switches to fine measurement mode with higher resolution; when temperature changes rapidly, it uses coarse mode with lower resolution. This dynamic adaptation achieves high precision when needed while consuming less power overall compared to continuously operating at maximum resolution.
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
This approach provides a substantial increase in temperature resolution, exceeding traditional methods, enabling accurate measurements with a resolution of 0.001°C or better and sample rates of up to 10 kHz, while maintaining low power consumption, suitable for long-term battery-powered operations.
Implementation Method 1
temperature measurement with a resistive temperature measurement sensor
Implementation Method 2
charge time measurement unit (CTMU) for measuring a fine time
Data Source
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AI summary
Temperature is determined by measuring the time it takes to charge a capacitor with a resistive temperature sensor. A clock, time counter, a voltage comparator and voltage reference are used in determining a coarse time measurement. The time measurement resolution is enhanced with the addition of a constant current source charging another timing capacitor within a single clock pulse time to provide a fine time measurement.