Definition
A laboratory irradiator is a scientific instrument that applies electromagnetic radiation (such as ultraviolet, visible, X-ray, etc.) or particle radiation (such as electron beam) or particle radiation (such as electron beam) to a sample under controlled conditions to simulate, study, or test the response of materials in a radiation field. It is widely used in materials science, environmental research, agricultural biology, food science, and industrial product aging testing, and is a key equipment for evaluating material photostability, radiation effects, and photochemical research.
Principle
The core working principle of laboratory irradiators is based on the interaction of electromagnetic radiation, or particle radiation, with matter. For common light irradiators, the light source (such as xenon lamp, mercury lamp, LED array) emits light radiation with a specific spectral distribution, which is screened out by an optical filter system or monochromator to evenly irradiate the sample surface. Radiation energy is transferred to the sample, which can trigger photophysical or photochemical reactions, such as molecular excitation, chemical bond breaking, free radical generation, etc. The radiation dose is usually determined by the product of irradiance (radiation power received per unit area, often in W/m²) and exposure time, and can be expressed as:
H = E × t
H represents radiation exposure (usually in J/m²), E represents the irradiance of the sample surface, and t represents the exposure time. The instrument monitors and controls irradiance in real time through sensors to ensure accuracy and repeatability of experimental conditions.
Measurement method
When conducting experiments with laboratory irradiators, standardized measurement methods are essential. First, parameters such as radiation spectral distribution (e.g., simulated solar spectrum), irradiance level, sample temperature, ambient humidity, and cycle cycle need to be set according to test standards (e.g., ASTM G155, ISO 4892 series, etc.) or research objectives. The sample is placed on a sample tray or holder to ensure that the irradiated surface receives light evenly. The radiation dose is measured and verified at the sample plane with a calibrated radiometer or spectrometer. For aging tests, changes in sample color, luster, mechanical properties, or chemical structure are often evaluated periodically. To ensure data comparability, experiments often include reference samples and strict environmental controls.
Influencing factors
The test results of laboratory irradiators are influenced by a variety of factors. The spectral power distribution and stability of the light source directly determine the authenticity of the radiation conditions. The uniformity of the optical system affects the consistency of the dose received across parts of the sample. Environmental parameters such as ambient temperature, sample surface temperature, relative humidity, and air flow velocity may change the photochemical reaction rate of the material. The sample's own characteristics, such as thickness, color, light transmittance, and surface morphology, can also affect radiation absorption and internal dose distribution. In addition, the calibration status of the instrument, the maintenance interval and the standardization of the operator are all important links to ensure data reliability.
Application:
Laboratory irradiators have a wide range of uses in several non-medical fields. In materials science, it is used to evaluate the weathering resistance and aging behavior of polymer materials, coatings, textiles, and plastics under light radiation. In agricultural biology, the effects of different light quality and light intensity on plant growth and seed germination can be studied. In food science, it is used to simulate the stability of food ingredients or the protective properties of packaging materials under light conditions. In environmental research, it can be used to photocatalytically degrade pollutants or study the durability of materials in radiation environments. In industrial product testing, it is a common tool for performance verification of lamps, photovoltaic materials and automotive exterior parts.
Selection
Choosing the right laboratory irradiator requires comprehensive consideration of technical parameters and application requirements. First, the required radiation type (e.g., full-spectrum solar simulation, specific UV bands) and spectral matching requirements should be clarified. Irradiance adjustable range, uniformity and long-term stability are the key performance indicators. The size of the sample chamber and the ability to control temperature and humidity need to match the sample specifications and test standards. The user-friendliness of the instrument's user interface, data logging function, and safety protection measures (such as over-temperature protection, door lock interlocking) affect the user experience and safety. In addition, it is necessary to refer to the requirements of relevant international, national or industry standards for equipment, and evaluate the convenience of technical support, calibration services and equipment maintenance from suppliers to ensure that the instrument meets the testing needs of the laboratory throughout its life cycle.