Mbar, or milibar, is a unit for measuring vacuum pressure. Vacuum pressure means the pressure in a system that is lower than atmospheric pressure. In absolute terms, a perfect vacuum is zero mbar, while atmospheric pressure at sea level is approximately 1013 mbar. Earlier, Torr was used as a unit to measure pressure. But today, mbar has replaced it. Let us understand more about it.
What Is Vacuum Pressure? Â
Vacuum pressure is a measure of the pressure of a gas in an area where the pressure is below the atmospheric pressure. It is shown as a negative gauge pressure. The official unit for measuring the gas pressure in a vacuum is Pascal (Pa). However, mbar has become a prevalent measuring unit in Europe.
How Do You Measure Vacuum Pressure? Â
Vacuum pressure is measured using various gauges. Each one is for specific pressure ranges and operating conditions.
Mechanical vacuum gauges, like Bourdon tube gauges, measure pressure directly by recording the force acting on a diaphragm’s surface. These gauges are effective in the range from approximately 1000 mbar (atmospheric pressure) down to 1 mbar.
Thermal conductivity gauges such as Pirani gauges are available for medium vacuum ranges. They measure heat loss from a heated wire, which decreases with the reduction in pressure. These gauges are most suitable for measuring vacuum ranges from 1000 mbar down to 10-3 mbar.
In high to ultra-high vacuum ranges, ionization gauges, like hot cathode ionization gauges, are crucial. They measure ultra-high vacuum ranges by ionizing gas molecules and measuring the resultant current of ions.
To select the right gauge, consider factors such as the desired pressure range and the operating environment. For instance, a sophisticated measuring instrument is essential in challenging conditions where contamination or vibrations are concerns.
No specific technology or instrument can measure across the whole vacuum range. This is why different gauges are there to monitor vacuum systems.
What Is Vacuum Mbar? Â
1 mbar equals to 100 Pascals. A typical home vacuum cleaner can achieve around 209 mbar, while industrial vacuum pumps can reach very low pressures, like 965 mbar. This indicates a high level of vacuum efficiency.
For example, the mbar in Leybold vacuum pumps is as high as 1050 mbar.
This pump can safely operate with inlet pressures up to slightly above standard atmospheric pressure (1,013 mbar at sea level). This means it is capable of handling processes where the gas pressure at the inlet is not over 1,050 mbar. If this limit is exceeded, it could potentially damage the pump or reduce its efficiency.
Different Vacuum Ranges  Â
Vacuum pressures are categorized into several ranges based on their values:
1. Low Vacuum: 1000 mbar to 1 mbar
2. Medium vacuum: (FV) 1 – 10(-3) mbar
3. High vacuum: (HV) 10(-3) – 10(-7) mbar
4. Ultra-high vacuum: (UHV) 10(-7) – 10(-14) mbar
5. Extreme high vacuum: < 10(-12)
Ranges of Industrial Vacuum Systems  Â
Rough, middle, and high vacuum are the three categories of industrial vacuum systems.
 a. Rough vacuum Â
Rough vacuum is the pressure ranging from atmospheric pressure down to nearly 1 mbar. This range is typically used by vacuum pumps that do not require very low pressures. You will find them in packaging, drying, and general manufacturing processes. Rough vacuum systems can be achieved using vacuum pumps with less complex designs.
Leybold’s diaphragm pumps run in the low vacuum ranges. They do not achieve high compression ratios with one stage. They can produce a typical operating range from the atmosphere to the low mbar range. Multi-stage root pumps compress atmospheric pressure to the low 10(-2)  mbar range. They are a dry pumping alternative to scroll pumps, which need particle-free pumping.
 b. Medium Vacuum Â
A medium vacuum is a vacuum with an absolute pressure between 1 mbar and 10(-3)Â mbar. Medium vacuum pressure is used in applications like coating, chemical analysis, and some semiconductor industries, such as deposition and etching. It imparts a controlled environment with minimized pressure. For this vacuum pressure range, sophisticated pumping systems are integral as they maintain the required pressure levels.
Leybold’s scroll pumps are typical examples of medium vacuum pumps. They have a pressure range of 103 to 10-2 mbar and use two inter-leaved Archimedean spiral scrolls to compress gases. They are used in analytical instruments, like mass spectrometry, and in electronic microscopes due to the requirement of clean, dry, and quiet vacuum.
 c. High vacuumÂ
As already mentioned above, high vacuum is in the range of 10(-3) – 10(-7) mbar. High vacuum is important for research in particle physics, electron microscopy, and some manufacturing processes like foil packaging through metal evaporation and layering it onto a plastic film.
Food is also freeze-dried via high vacuum technology to reduce spoilage and extend freshness. These applications demand very low levels of gas molecules in the environment, and so achieving high vacuum requires multi-stage pumping systems and specialized equipment.
Conclusion Â
Understanding the vacuum pressure range in mbar is critical when selecting a pump, as it directly determines its suitability for your application. This is especially crucial when you are choosing the Leybold vacuum pump on our website. A vacuum range that is not enough for your needs degrades the performance of your system and damages it. Whether it’s a laboratory process, industrial filtration, or a vacuum clamping system, the right vaccum range will help enhance the process. Explore our site or feel free to contact us for your vacuum pump needs.
Frequently Asked Questions Â
1. What are the main types of vacuum pumps?
In industrial vacuum systems, primary pumps, booster pumps, and secondary or high vacuum pumps are used to achieve vacuum pressure ranges like high, very high, and ultra-high.
2. What is the best vacuum pump for car maintenance?
The rotary vane vacuum pump by Leybold is ideal for car maintenance. It can achieve high vacuum levels, which is needed for the thorough evacuation of AC systems.
3. What is the maximum vacuum pressure in mmHg?
Ultra-high vacuum, which is below 10(-9)Â mmHg, is typically considered maximum. Note that a perfect or 100% vacuum is impossible to get.
4. Is 10 mbar a high vacuum?
No. A 10 mbar vacuum pressure is a medium vacuum. It is is the range 1 mbar to 10(-3)Â mbar, which translates to 0.001 mbar.
