Many users are confused about the readings on the vacuum drying oven and the relationship between the atmospheric pressure and the vacuum degree.
Firstly, the atmospheric pressure is a general name, the normal pressure state is usually called a standard atmospheric pressure, (101325 Pa) ≈ 100000Pa = 100KPa = 0.1MPa, each place will be slightly deviated due to geographical location, altitude, temperature, etc.
Secondly, the vacuum degree is the pressure value lower than the atmospheric pressure, usually the negative value is changed to a positive value, taking the vacuum drying oven parameters manufactured by Kenton for example, the maximum vacuum degree is marked as <133Pa, that is, <0.133kPa, <0.000133MPa, which means that the maximum vacuum degree is less than close to 0 MPa. (Note: The absolute vacuum pressure of 0 is impossible to achieve)
Lastly, the reading of the vacuum oven is lower than the atmospheric pressure value, the range is 0MPa-0.1MPa, note that the display here is a negative value, the range is equivalent to the atmospheric pressure from one atmosphere to close to 0 atmosphere, and the vacuum degree (because the vacuum degree is a negative value changed to a positive value) is equivalent to <133Pa.