Dual Mode Temperature Controller for Refractive Index Sensor
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Solution Overview
Problem
Existing index of refraction (IoR) sensors face challenges in achieving accurate measurements at a consistent temperature, particularly in real-world settings where samples may be outside the desired measurement temperature, leading to increased time and error in temperature stabilization.
Innovation Solution
A sensor system utilizing a dual mode temperature controller with spike mode and PID mode, coupled with heating and cooling elements, and multiple temperature sensors to rapidly achieve and maintain a sampling temperature setpoint, reducing the time needed for temperature stabilization and minimizing measurement errors.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Measurement precision
If a single mode PID temperature controller is used, then the system structure is simple, but the temperature stabilization time is long and measurement accuracy is reduced when samples are outside the desired temperature
Solution Approach 1:
The temperature controller dynamically switches between two operational modes (first mode for rapid temperature change, second mode for precise maintenance) based on real-time temperature feedback. This dynamic adaptation allows the system to optimize both heating/cooling speed and measurement precision, resolving the contradiction between fast stabilization and accurate measurement.
Solution Approach 2:
The system changes control parameters by switching between two distinct temperature control modes. The first mode uses aggressive heating/cooling parameters to quickly bring the sample near the target temperature, while the second mode uses precise maintenance parameters to hold the temperature within the measurement window, thereby achieving both fast response and high precision.
2Speed
If aggressive heating or cooling is applied to quickly reach target temperature, then the temperature stabilization time is reduced, but the system may overshoot the target temperature and require additional correction time
Solution Approach 1:
The system continuously monitors the sample temperature and uses this feedback to determine when to switch from the first temperature control mode to the second mode. This feedback mechanism ensures that aggressive heating or cooling is applied only when necessary and is discontinued when the sample approaches the target temperature, preventing overshoot and maintaining control stability.
Solution Approach 2:
The temperature controller periodically evaluates the temperature difference between the sample and target, switching between aggressive adjustment (first mode) and gentle maintenance (second mode) based on this periodic assessment. This periodic action allows the system to achieve fast response when needed while ensuring stable control near the target temperature.
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
The system enables highly accurate IoR measurements by quickly and efficiently stabilizing the sample temperature within a specified tolerance, reducing the time required to reach the measurement temperature and minimizing errors associated with temperature compensation.
Implementation Method 1
one or more heating and cooling elements thermally coupled to a sample chamber
Implementation Method 2
one or more heating and cooling elements thermally coupled to a sample chamber
Implementation Method 3
a first temperature sensor coupled to the sample chamber and a second temperature sensor coupled to the one or more heating and cooling elements
Implementation Method 4
When light traveling from a high index medium is incident upon an interface between the high index medium and another medium having a lower refractive index at angles of incidence larger than a critical angle of incidence, total internal reflection may be observed
Implementation Method 5
Index of Refraction (IoR) sensors... utilize principles of physics underlying the measurement of critical angle to determine refractive index of a medium
Data Source
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AI summary
A sensor system (100) utilizes temperature control systems (262) and methods to achieve and maintain a sample in a sample chamber (110) at a sampling temperature. Such sensor systems and methods may employ a dual mode temperature controller including a spike mode (SMC) controller (274) and a proportional-integral-derivative (PID) mode controller (272). Based on a temperature of the sample, the temperature controller of the sensor system can initially enter the spike mode or the PID mode.