In many fields such as scientific research, biotechnology, automatic control, environmental protection, and water treatment, gas sampling, gas circulation, and object adsorption are often required. In this case, imported vacuum pumps are needed. Its main parameters include vacuum degree, flow rate, etc.
1. "Vacuum degree" generally refers to the maximum pressure that a pump can reach during operation, that is, the degree of thinness of the remaining gas after it is extracted from a sealed container.
In industry, there are two ways to represent extreme pressure. One is "absolute pressure", which means using "absolute vacuum" (an absolute vacuum that can only be achieved theoretically and has no substance) as the zero position, and the marked values are all positive. The smaller the number, the closer it is to absolute vacuum, which means the higher the vacuum degree. For example, we have a "high vacuum" micro vacuum pump. Its ultimate pressure is 10KPa (0.01MPa), which belongs to the category of high vacuum degree in micro vacuum pumps.
Another type is "relative pressure", which means using atmospheric pressure as the zero position and negative values below atmospheric pressure, hence it is called "negative pressure". The larger the absolute value of this negative value, the higher the vacuum degree.
The most commonly used and scientific method in the international vacuum industry is to use the "absolute pressure" label; But because the method of measuring relative pressure is simple and the measuring instruments are common (such as general vacuum gauges which are relative pressure gauges), it is customary in China to use "relative pressure" to indicate.
The relationship between the two: relative pressure=absolute pressure - local atmospheric pressure.
For example, absolute pressure: 10Kpa, its relative pressure=10-100=-90Kpa (-0.09MPa).
2. In fields such as scientific research, laboratories, and healthcare, gas pressurization is often applied, such as injecting gas into a container with positive pressure, or having high resistance in the system that requires a pump to overcome resistance and deliver gas. At this point, the pump needs to be able to output a positive pressure higher than atmospheric pressure, usually expressed as "relative pressure". Our high-pressure micro air pump and micro vacuum pump can output a maximum positive pressure of>100Kpa (0.1MPa). They belong to dry vacuum pumps and do not require imported vacuum pump oil and lubricating oil. They do not pollute the working medium and can operate continuously for 24 hours. Both the suction and exhaust ends can be blocked, making them particularly suitable for these occasions.
The commonly used "vacuum degree" in the international vacuum industry refers to "extreme vacuum, absolute vacuum degree, and absolute pressure", but "relative vacuum degree" (relative pressure, vacuum gauge pressure, negative pressure) is more widely used due to its simple measurement method and widespread measurement instruments.
Conversion formula: relative vacuum degree=standard atmospheric pressure - absolute vacuum degree
For example, if the absolute vacuum degree is 80KPa, its relative vacuum degree is about 100-80=20KPa, and it should be displayed as -0.02MPa on the relative vacuum gauge.
Simply put, these three concepts correspond to the rarefied, normal, and dense states of gases.
Atmospheric pressure: refers to an atmospheric pressure, which is the gas pressure generated by the atmosphere in which we usually live. A standard atmospheric pressure is 101325 Pa (Pa, Pascal - commonly used unit of pressure). 100000Pa=100KPa, so we often use 100KPa or 101KPa to represent a standard atmospheric pressure. Due to differences in geographical location, altitude, temperature, and other factors, the actual atmospheric pressure in each area is not equal to the standard atmospheric pressure. However, for simplification purposes, sometimes atmospheric pressure can be approximated as a standard atmospheric pressure of 100KPa;
Negative pressure refers to the state of gas that is lower than atmospheric pressure, also known as "vacuum". For example, when drinking beverages through a tube, there is negative pressure inside the tube; The suction cup used for hanging things also has negative pressure inside.
Positive pressure: refers to a gas state that is higher than atmospheric pressure. For example, when inflating a bicycle or car tire, the output end of the pump or pump produces positive pressure.
