Definition
The temperature and humidity three integrated vibration test chamber is a compound environmental reliability test equipment that integrates temperature, humidity and vibration environment simulation functions. It systematically integrates the temperature and humidity test chamber with the shaker table to realize the simultaneous application of mechanical vibration excitation under controlled temperature and humidity conditions to simulate the complex comprehensive environmental stresses that the product may encounter during actual use or storage.
Principle
The working principle of this device is based on the coordinated work of multiple subsystems. The temperature control subsystem usually uses compressor refrigeration and electric heater to heat, and the air temperature in the box changes according to the set program through forced air circulation and precise PID adjustment. The humidity control subsystem controls the ratio of dry and wet air, and common methods include steam humidification and refrigeration and dehumidification to achieve precise control of relative humidity. The vibration subsystem consists of a vibration controller, a power amplifier and an electric shaker, which generates electrical signals of specific waveforms (such as sine and random), and drives the shaking table coil to generate the required mechanical vibration after amplification. The central control system coordinates these three subsystems synchronously to ensure that the temperature and humidity conditions are precisely coupled with the vibration load in time.
Measurement and calibration methods
The performance of the equipment needs to be measured and calibrated according to relevant national or international standards. Temperature measurements typically use traceable calibrated platinum resistors or thermocouples with multiple measurement points arranged in the workspace within the chamber to assess temperature uniformity and fluctuations. Humidity measurement mostly uses precision dew point meters or capacitive humidity sensors for comparison. The measurement of vibration parameters relies on an accelerometer mounted on a vibrating table, and its signal is connected to the analyzer via a charge amplifier to calibrate the vibration frequency, amplitude, root mean square value of acceleration, and table uniformity. During the comprehensive test, it is necessary to verify whether the control accuracy and synchronization of each parameter meet the standard requirements under the condition of simultaneous temperature and humidity cycle and vibration, such as referring to the relevant parts of GB/T 10586, IEC 60068-2 series and other standards.
Influencing factors
The accuracy and repeatability of the test results are affected by multiple factors. The equipment itself includes temperature and humidity uniformity in the workspace, lateral movement and distortion of the vibrating table, and interference when the systems are coupled. The mass, size, heat capacity and load distribution of the specimen can change the dynamic characteristics of the airflow field and shaker table in the chamber, thus affecting the actual environmental conditions. In addition, the setting of test parameters, such as temperature change rate, humidity cycle stage, vibration spectrum and magnitude, needs to be scientifically designed according to the actual environment of the product, and improper stress application may lead to over-tested or under-tested.
Applications
The temperature and humidity three integrated vibration test chambers are widely used in the product development and quality verification stages with high reliability requirements. In the field of automotive electronics, it is used to test the durability of automotive components under the combined conditions of day and night temperature differences, moisture and road bumps. In the aerospace field, it is used to evaluate the functional integrity of airborne equipment in rapid temperature changes, high humidity and flight vibration environments. In industries such as consumer electronics, industrial control, new energy, and military equipment, the device is also used to simulate the complex environments encountered by products in transportation, storage, and use to find design flaws and screen potential faults to improve product reliability.
Selection considerations
Equipment selection is a technical decision-making process that requires comprehensive trade-offs. First, it is necessary to clarify the test requirements, including the size and weight of the specimen, the required temperature range and temperature change rate, the humidity range, and the vibration thrust, frequency range, and displacement. Secondly, it is necessary to evaluate the technical indicators of the equipment, such as temperature uniformity, humidity control accuracy, acceleration distortion and signal-to-noise ratio of the vibrating table. The structural reliability of the equipment, long-term operational stability, and the ease of use and programming flexibility of the control software are also important considerations. In addition, the installation conditions of the laboratory, such as the load-bearing capacity of the site, power capacity, cooling water supply, and heat dissipation and noise during equipment operation, are also considered. It is recommended that users have detailed technical communication with equipment suppliers according to the specific requirements of their own testing standards to choose models with high adaptability.