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Understanding Temperature and Humidity Control in Benchtop Environmental Chambers
2025-06-05
As an important environmental testing equipment, benchtop environmental chamber is widely used for environmental adaptability testing of electronic components, material samples, medical devices and other products.
To ensure the accuracy of benchtop environmental chamber test results, accurate temperature and humidity control is essential.
In this article, we will explore the basic principles of benchtop environmental chamber temperature and humidity control, and how they ensure the accuracy of test results.
In addition, if you are currently hesitating between desktop and floor-standing models, you can refer to our related article "Benchtop vs Floor-standing Environmental Chambers: Which One Fits Your Needs?" to help you choose a more suitable solution for your laboratory and production line.
What Is a Benchtop Environmental Chamber?
The benchtop environmental chamber (such as a benchtop programmable constant temperature and humidity test chamber ) is a compact chamber that is convenient for testing small products in a limited space and suitable for convenient temperature and humidity evaluation of small devices. It is widely used in R&D and quality inspection in the fields of electronics, medical treatment, materials, new energy, etc.
Principle of Temperature Control
In a benchtop environmental chamber (such as a benchtop high and low temperature test chamber), the core of temperature control is to maintain the temperature in the test chamber at a set level so that it remains stable during the test. The basic principle of temperature control is to monitor the temperature changes in the test chamber in real time through a temperature sensor, and the control system issues instructions to the heating and cooling devices to adjust the temperature balance.
Components of a Temperature Control System
Temperature sensor: used to detect the actual temperature in the test chamber, such as Thermocouple and platinum resistor (PT100). Thermocouple has a fast response speed and can be used to test products that require rapid temperature changes; PT100 platinum resistor is famous for its high accuracy and stability, and is suitable for testing products with high temperature control accuracy.
Heating system: Most test chambers use electric heaters (such as nickel-chromium alloy heating wires or ceramic heating elements), and the heating power is adjusted by switch control. When the temperature is lower than the set value, the heating system will start and quickly increase the temperature in the test chamber.
Refrigeration system: The refrigeration system is another key part of the environmental test chamber, and most of them adopt a compressor refrigeration cycle structure. It consists of a compressor, a condenser, a throttling device, and an evaporator: the compressor compresses the low-pressure refrigerant into a high-pressure gas, which releases heat through the condenser and becomes a high-pressure liquid. After the throttle valve reduces the pressure, it enters the evaporator to absorb heat and achieve cooling. This cycle can achieve a rapid switch from normal temperature to low temperature, ensuring that the test environment reaches the required conditions in a short time. Some equipment also supports cascade refrigeration and environmentally friendly fluorine-free refrigeration systems to meet the needs of higher temperature gradients and environmental protection standards.
PID controller: PID controller is a commonly used temperature control technology that uses three algorithms, proportional (P), integral (I) and differential (D), to work together to accurately control temperature changes. It can analyze the deviation between the actual temperature and the set value in real time, respond quickly and adjust the heating or cooling output, thereby effectively avoiding temperature overshoot and fluctuations, maintaining the stability of the test environment, and improving the reliability and repeatability of test results.
These systems work together to quickly switch between different temperatures and keep the temperature within a very small error range (such as ±0.5°C) to meet high-standard test requirements. This high-precision temperature management not only ensures the reliability of the test environment, but also effectively meets the strict standards for environmental simulation in industries such as electronics, medicine, and new energy, helping users obtain more accurate test results.
Principles of Humidity Control
In environmental experiments, humidity can be expressed in two ways: relative humidity and absolute humidity. Relative humidity indicates the ratio of the actual water vapor content in the current air to the maximum water vapor content that the air can hold at the same temperature, usually expressed as a percentage (such as 60%RH). Absolute humidity is the actual mass of water vapor contained in a unit volume of air (usually expressed in g/m³), and is generally not affected by temperature changes.
In practical applications, relative humidity is more commonly used because it directly reflects the feeling of "wetness" and "dryness" of the air and is closely related to temperature.
How Humidity Control Is Achieved
In the benchtop environmental chamber, humidity control is usually achieved through humidification and dehumidification. The humidification and dehumidification systems are adjusted in real time by humidity sensors and controllers to maintain the preset humidity level.
Humidification system: Common methods include steam humidification (generating water vapor by heating water) and ultrasonic humidification (atomizing water and releasing it into the air).
Dehumidification system: Mainly achieved through condensation dehumidification (cooling the air to the dew point so that the water vapor condenses into water droplets and is discharged) and desiccant moisture absorption.
The Correlation Between Temperature and Humidity
Temperature and humidity are closely related, and relative humidity is completely dependent on temperature. The water content in the air increases with increasing temperature, so without changing the water content, simply increasing the temperature will also reduce the relative humidity. Conversely, lowering the temperature will increase the relative humidity.
This means that when controlling humidity, the temperature must be controlled simultaneously, otherwise even if the water vapor content does not change, the relative humidity may fluctuate violently due to temperature changes, resulting in an unstable test environment. Therefore, the humidity control system in the benchtop environmental chamber always works in conjunction with the temperature control system to ensure the accuracy and consistency of the test results.
Key Features of Temperature and Humidity Control in Benchtop Chambers
Modern benchtop environmental chambers integrate many advanced technologies in temperature and humidity control to ensure the accuracy and repeatability of test results and meet the high standards of various industries.
High control accuracy: A good benchtop environmental chamber usually has excellent temperature and humidity control, such as temperature control accuracy of ±0.5℃ or even higher, and humidity control accuracy is generally within ±2%RH. This precision control ensures that the product remains stable during the test, which is also the prerequisite for obtaining reliable experimental data.
Intelligent control system: Most test chambers are equipped with PID temperature and humidity controllers, which use proportional-integral-differential algorithms to achieve precise adjustment of temperature and humidity to prevent temperature and humidity overshoot and fluctuations. In addition, digital touch screen control has become mainstream, which can provide real-time display, programming settings, curve graphics, alarm prompts and other functions. It is intuitive and convenient for users to operate, which can greatly improve the user experience.
Calibration verification support: In order to meet the requirements for data traceability, many benchtop environmental chambers support third-party temperature and humidity calibration interfaces (such as for inserting standard sensors for comparison), regular self-calibration reminder functions, data recording and export. These functions can be applied to industries that have strict requirements on data accuracy, such as medical, aviation, semiconductor, etc.
Faqs About Temperature and Humidity Control in Benchtop Environmental Chambers
1. What Is Temperature Control?
Temperature control refers to the process of maintaining the temperature in a specific space and system within a predetermined range by means of heating and cooling. This process usually relies on the coordinated work of temperature sensors, controllers and heating/cooling equipment to achieve the regulation of ambient temperature.Precise temperature control not only ensures the stability of the test environment, but also effectively simulates various extreme working conditions, thereby meeting the strict requirements of environmental testing in multiple industries such as electronics, materials, and medicine.
2. What Is Humidity Control?
Humidity control is the process of monitoring and regulating the water vapor content in the air, aiming to maintain the relative humidity within a set range to meet the specific needs of human comfort and industrial applications. Through humidification or dehumidification equipment, humidity control systems can effectively prevent mold growth, corrosion reactions, material deformation and other problems caused by humidity fluctuations, and are widely used in laboratory environments, electronic manufacturing, cultural relics preservation and clean rooms.
3. Can Benchtop Environmental Chambers Control Humidity Without Controlling Temperature?
Benchtop environmental chambers can control temperature and humidity at the same time, because humidity control often depends on temperature stability. Relative humidity is the ratio of the actual water vapor content in the air to the saturated water vapor content. The "water holding capacity" of air increases with rising temperature. The higher the temperature, the more water vapor the air can hold. The lower the temperature, the easier it is for water vapor in the air to reach saturation, forming dew or condensation. Therefore, controlling humidity must rely on temperature stability. In order to accurately control the humidity of the benchtop environmental chamber, you must also control the temperature.
4. Why Is Precise Temperature and Humidity Control Required in the Benchtop Environmental Chamber?
Accurate temperature and humidity control is essential to ensure the consistency of test results. Slight fluctuations in temperature and humidity may affect material properties and the working state of electronic components, leading to deviations in test results, which in turn affects the overall quality and reliability of the product. If you want to know how to choose a high-quality controller, you are also welcome to read our other article: "What Makes a High-Quality Stability Chamber Controller" This article will help you gain a deeper understanding of the core features of the controller and assist in your equipment procurement and test management.
5. Does the Temperature and Humidity Control System of the Benchtop Environmental Chamber Need to Be Calibrated Regularly?
Yes. In order to ensure the traceability and accuracy of the data, the temperature and humidity control system of the benchtop environmental chamber should be calibrated regularly. Through third-party standard sensors or built-in calibration functions, it is possible to verify whether the control system is operating within the set error range to avoid deviations in the equipment after long-term operation, thereby affecting the accuracy of the experimental results.
Conclusion
Through this article, I hope you can understand temperature and humidity control in benchtop environmental chambers. If you want to customize a benchtop environmental chambers solution, please feel free to contact Guangdong Zhongzhi Testing Instruments Co., Ltd. and let us make the right choice for you and provide you with technical. Zhongzhi can customize various environmental simulation chambers for different industries. Whether you need to use a temperature humidity environmental chamber for precision testing, or conduct accelerated testing through an environmental stress chamber, or using an environmental temperature test chamber to perform diverse temperature cycling tests, we can provide you with the right solution to help you complete your testing work efficiently. In addition, if you are interested in our content, you are also welcome to read other articles:
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