Test chamber and method for conditioning of air
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Solution Overview
Problem
Existing test chambers face challenges in precisely controlling relative humidity due to interference between temperature and humidity control circuits, leading to complex and error-prone software, especially when temperature and humidity changes counterbalance each other, resulting in overshoot and prolonged settling times.
Innovation Solution
Implementing a method where the humidifier control circuit uses absolute humidity as a control variable, allowing the test chamber control circuit and humidifier control circuit to operate independently, eliminating counterbalancing issues and enabling precise humidity control by measuring absolute humidity with a humidity sensor, which remains constant despite temperature changes, thereby simplifying calibration and reducing spatial humidity measurements.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Adaptability or versatility
If the test chamber control circuit and humidifier control circuit operate independently to control temperature and relative humidity, then both temperature and humidity can be regulated, but the control circuits work against each other causing counterbalancing effects and prolonged settling times
Solution Approach 1:
The patent implements a cascade control system where the humidifier control circuit acts as a slave controller that receives feedback from the test chamber control circuit. The master controller (test chamber control circuit) sends feedback signals to the slave controller (humidifier control circuit) to coordinate their operations, preventing counterbalancing effects and reducing settling time while maintaining both temperature and humidity regulation capabilities
2Measurement precision
If the control device is programmed to handle counterbalancing effects between temperature and humidity control, then control accuracy can be maintained, but the software becomes considerably more complex and error-prone
Solution Approach 1:
The cascade control system with feedback from the master controller to the slave controller provides automatic coordination between temperature and humidity control circuits. This feedback mechanism eliminates the need for complex software programming to handle counterbalancing effects, as the control logic is inherently managed through the feedback loop, maintaining control accuracy while simplifying the software architecture
Solution Approach 2:
The master controller acts as an intermediary between the temperature control and humidity control circuits. It receives feedback from both circuits and coordinates their operations, serving as a mediator that prevents counterbalancing effects without requiring complex software logic in either control circuit, thus reducing overall system complexity while maintaining control accuracy
3Extent of automation
If relative humidity is used as the control variable, then humidity control is implemented, but control deviation occurs due to exponential relationship with temperature and controller gain issues
Solution Approach 1:
The patent changes the control variable from relative humidity to absolute humidity in the humidifier control circuit. This parameter change eliminates the exponential relationship with temperature that causes controller gain issues and control deviation. By using absolute humidity as the feedback variable, the control system achieves more precise and stable humidity control without the complications introduced by temperature-dependent relative humidity measurements
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 enhances control accuracy, reduces the complexity of software, and allows for simultaneous temperature and humidity regulation, achieving a ±1% tolerance in absolute humidity control, improving the overall control quality and eliminating interference between temperature and humidity control loops.
Implementation Method 1
a temperature control device for tempering the air in the test chamber
Implementation Method 2
a temperature control device for tempering the air in the test chamber
Implementation Method 3
a humidifier for humidifying the air in the test chamber
Data Source
AI summary
The invention relates to a method for conditioning the air of a test chamber (11), a test chamber (10), and a test chamber, in particular a climate chamber or the like, wherein test material (12) is arranged in the test chamber, which is sealable from the environment and temperature-insulated, wherein the air in the test chamber is tempered by means of a temperature control device of the test chamber and humidified by means of a humidifier of the test chamber, wherein the temperature of the air in the test chamber is measured with a temperature sensor (18, 19) of a test chamber control loop of a control device of the test chamber, wherein the temperature is controlled by means of the temperature control device by means of the test chamber control loop, wherein the humidity of the air in the test chamber is measured with a humidity sensor (22) of a humidifier control loop of the control device, wherein the humidity of the humidifier is controlled by means of the humidifier control loop.where the humidity sensor measures the absolute humidity in the test chamber, and the humidifier control loop regulates the humidity according to the absolute humidity as the control variable.