The measurement standard technology of UV Vis spectrophotometer involves the measurement and calibration of its accuracy, precision, and stability. This device is mainly used to detect changes in sample absorbance, in order to obtain concentration information of the sample. The core of its measurement standard technology lies in ensuring the reliability of equipment, and common calibration methods include the following aspects:
Light source calibration: UV visible spectrophotometers typically use deuterium lamps (UV spectroscopy) and tungsten lamps (visible spectroscopy) as light sources, ensuring the stability of the light source is crucial for the measurement of the instrument. By calibrating the intensity of the light source, measurement errors caused by fluctuations in the light source can be eliminated.
Wavelength calibration: The wavelength accuracy of the instrument is crucial for the experimental results. The common calibration method is to use standard substances with known absorption peaks (such as aniline, boron tetrafluoride, etc.) for calibration. By comparing the absorption peak of the standard substance with the wavelength output of the instrument, the instrument can be adjusted to ensure its wavelength accuracy.
Optical path calibration: The alignment of the optical path will affect the light absorption rate of the sample, so it is necessary to regularly check and calibrate the alignment of the optical path. Testing with standard solutions or specific wavelength filters can ensure stable optical paths.
Absorbance calibration: Use a standard solution of known concentration (such as oxalic acid, nitric acid, etc.) for absorbance calibration. By measuring the absorbance of solutions of different concentrations, the linear range and response sensitivity of the instrument can be verified.
Instrument validation and quality control: In daily use, instruments should be regularly validated and quality controlled to ensure their stable performance over long-term use. The use of standard reference materials is an important means of verifying equipment performance, especially when conducting precise experiments.
Through these measurement standard techniques, the accuracy and consistency of UV visible spectrophotometers can be ensured in different experiments, avoiding experimental deviations caused by instrument errors.