pH meters are an essential tool in the laboratory, used to measure the level of acidity and basicity of a solution, which is important for performing a variety of scientific experiments. In order for the results to be accurate, it is necessary to calibrate the pH meter on a regular basis to ensure that it is working properly. 

The PH meter is the most commonly used measuring device in laboratories; it is designed to measure the acidity or alkalinity of a solution, therefore, it offers important benefits for all laboratories; in laboratories, the use of PH meters significantly improves the accuracy of the results. 

Calibration of a rotary evaporator is a mandatory task to ensure good performance and operational safety in the laboratory. There are several methods to calibrate a rotary evaporator and they should be chosen based on the application, complexity and economic requirements. Researchers have tested and compared several ways to calibrate a rotary evaporator to determine which offers the greatest efficiency in different situations.