We were discussing the basic definition and significance of Pascal’s Law along with its derivation and also the concept of vapour pressure and cavitation in our previous posts.

Now we will understand here the concept of Absolute pressure, Gauge pressure, Atmospheric pressure and Vacuum pressure with the help of this post.

Pressure on a fluid will be measured with reference to some datum. Pressure on a fluid will be measured in two different systems. In first system, pressure will be determined by taking the absolute zero pressure or complete vacuum as datum line and it will be termed as absolute pressure.

While in second system, pressure will be measured by taking atmospheric pressure as datum line.

Absolute pressure

Absolute pressure is basically defined as the pressure which will be measured by taking absolute zero pressure or complete vacuum as datum line. Absolute pressure will be always positive.

Absolute zero pressure exists in complete vacuum where there will be no fluid molecules at all.

Gauge pressure

Gauge pressure is basically defined as the pressure which will be measured above or below the atmospheric pressure i.e. atmospheric pressure here will be taken as datum line.

Gauge pressure will be measured with the help of pressure measuring instrument. Atmospheric pressure will be marked as zero on the scale of pressure measuring instrument.

Pressure measuring instrument will measure the pressure difference between the liquid to which they are attached and surrounding sir.

If pressure is measured above atmospheric pressure then it will be termed as positive gauge pressure and if pressure is measured below atmospheric pressure then it will be termed as negative gauge pressure.

Vacuum pressure

Vacuum pressure is basically defined as the pressure which will be measured below than the atmospheric pressure and therefore that measured pressure will be with negative sign and we will say it vacuum pressure or negative gauge pressure.

Atmospheric pressure

Atmospheric pressure is basically defined as the pressure exerted against a surface by weight of the air column over that surface.

Relationship between Absolute pressure, vacuum pressure and gauge pressure

Absolute Pressure = Atmospheric pressure + Gauge pressure
Vacuum Pressure = Atmospheric pressure -  Absolute pressure

Do you have any suggestions? Please write in comment box.
We will now discuss the measurement of pressure, in the category of fluid mechanics, in our next post.

Reference:

Fluid mechanics by R. K. Bansal

1. It is a great website.. The Design looks very good.. Keep working like that!. best vacuum cleaner for hardwood floors and pet hair

2. In this way, in the event that we subtract the amperage utilized by the force spout engine from our 12 amp machine, we think of 10.5 amps for the engine and light. 5 best

4. A very awesome blog post. We are really grateful for your blog post. You will find a lot of approaches after visiting your post. low volume injection molding

5. I really appreciate this wonderful post that you have provided for us. I assure this would be beneficial for most of the people. stereo mold

6. There are a few advantages you get from employing proficient cleaners. robot vacuums

7. Thanks for a very interesting blog. What else may I get that kind of info written in such a perfect approach? I’ve a undertaking that I am simply now operating on, and I have been at the look out for such info. best vacuum for pet hair

8. You know your projects stand out of the herd. There is something special about them. It seems to me all of them are really brilliant! read more

9. I am really enjoying reading your well written articles. It looks like you spend a lot of effort and time on your blog. I have bookmarked it and I am looking forward to reading new articles. Keep up the good work. best shark vacuum for vinyl plank floors

10. These are only a portion of the focuses you ought to consider while choosing another vacuum cleaner. dyson stair vacuum

11. Super site! I am Loving it!! Will return once more, Im taking your food additionally, Thanks. Acupressure Points

12. Many individuals purchase the main vacuum that looks mostly fair, since they don't care for vacuum cleaner shopping and need to spend their cash on things that appear to be all the more energizing. https://bestestofzuiger.com

13. We are really grateful for your blog post. You will find a lot of approaches after visiting your post. I was exactly searching for. Thanks for such post and please keep it up. Great work. footcare drill

14. We have sell some products of different custom boxes.it is very useful and very low price please visits this site thanks and please share this post with your friends. podiatry vacuum drills

15. You need your wedding outfit conservation to forestall earthy colored spots or oxidation spots on your dress. Earthy colored spots normally happen when a stain in the dress was not appropriately cleaned. same day air duct cleaning

16. A number of dissertation websites on the internet online in the event you obtain clearly declared in the website. Carpet Cleaners London

17. In case you are otherworldly or strict, or then again in the event that you take part in reflective practices, you might wish to fuse cleaning into these to scrub your home and assortment of negative energies.
empresas de limpieza en zaragoza

18. But armed with a few handy home improvement tips, you could be well on your way to the ideal home of your dreams. Most of these tips are easy to follow and will make deciding on home improvement projects a breeze for you.iRobot Roomba 614

19. Thanks for taking the time to discuss this, I feel strongly about it and love learning more on this topic. If possible, as you gain expertise, would you mind updating your blog with extra information? It is extremely helpful for me. soft washing

20. The essential reason to have an expert to clean your carpet is that they are certified and professional too. This is immensely important because a certified carpet cleaner knows exactly how to clean every kind of carpet. Water Damage Restoration Services

21. Assuming you look for that "balance" between pressure washing and family recollect that you are enabled to be in charge of your days. pressure washing service near Pittsburgh PA

22. Such sites are important because they provide a large dose of useful information ... animeflash

23. Thank you ever so for you blog article. Thanks Again. Cool. best reflow oven