A photometer is an instrument used to measure the intensity of light, which is widely used in scientific research experiments, pharmaceuticals, environmental monitoring and other fields. Its usage and calibration steps are essential to guarantee the accuracy of the measurement results. Below, let's explain in detail how to use the photometer and the steps of calibration.
First, the use of the photometer
Preparation.
Before using a photometer, there are some preparations to be made. Place the photometer on a stable bench to ensure that the photometer is not disturbed by external vibrations. At the same time, clean the measuring cell or tube to ensure that there are no impurities or scratches on its surface.
Set the measurement conditions.
Set the appropriate wavelength and measurement type according to the experimental requirements. Photometers typically have multiple wavelength options, and the measurement type can be set to absorbance (a), transmittance (t), or concentration (c), among others. Select the appropriate measurement conditions according to the needs of the experiment.
Sample handling.
Depending on the different characteristics of the sample, appropriate pretreatment is carried out. For example, for liquid samples, the pH value, dilution or dilution, etc., can be adjusted. For solid samples, treatment such as pulverization or dissolution may be required.
Sample measurement.
Transfer the sample to a pre-cleaned and dried measuring cell or tube, ensuring that the sample is filled parallel to the measurement beam. Avoid the presence of air bubbles that may affect the measurement results. Place the measuring cell or tube in a photometer and measure according to the measurement conditions.
Second, the calibration steps of the photometer
The calibration step of the photometer is to ensure the accuracy and reliability of the measurement results. The following is a general calibration.
Steps:Zero-point calibration.
Zero calibration is the DI step of photometer calibration. Clean the cell or tube, then fill it with a pure solvent (choose the appropriate one for your experiment). Adjust the absorbance value of the pure solvent to zero to ensure the accuracy of the zero point calibration.
Peak calibration.
Peak calibration is the DI second step of calibrating a photometer. Select the appropriate peak solution (select the appropriate peak solution according to the needs of the experiment) and adjust its measured absorbance value to a preset value. According to the measurement results of the peak solution, adjust the peak position of the photometer.
Linear calibration.
Linear calibration is the next step in photometer calibration. Choose two or more standard solutions, each with different absorbance values. The absorbance of these standard solutions is measured separately and the relationship between absorbance values and concentration is plotted as a curve. Adjust the linear range of the photometer according to the standard curve.
It is important to note that the calibration of the photometer should be performed regularly to ensure the accuracy of the measurement results. In addition, the luminaire's light source and detector should be checked for proper operation prior to calibration to avoid measurement errors due to equipment failure.
In summary, the method of using a photometer and the calibration steps are essential to obtain accurate and reliable measurement results. Only when the photometer is used correctly and calibrated regularly can the accuracy of the experimental results be ensured and provide strong support for scientific research and experiments. By having a good understanding of how to use the photometer and how to calibrate it, we are able to operate and manage the photometer more accurately.