Andy P

21-10-2016, 05:18 PM

Evening all,

During a club evening, the subject of pressure was brought up. Ambient and absolute that is. There was a distinct spilt in the 'discussion' and to say things got a little heated was an understatement.

It started with 'what is the water pressure at 15m', ' answer is 1.5bar' , that i managed to follow. THen it turned to atmospheric pressure, easy thats 1bar (at sea level excluding weather systems).

As i understand it, absolute pressure is 'atmospheric pressure at sea level (in this case 1bar) plus water pressure (in this case 15m which is 1.5bar) making a total of 2.5 bar.

Then ambient pressure was introduced......

It was suggested that ambient pressure was related to the medium that was being referred to. So, the 'ambient water pressure' at 15m was 1.5bar. This made sense to me as the definition of ambient pressure suggested this.

However, it was then said that this was not correct when related to diving and that ambient and absoulte pressure are the same.

Ive looked at this and they both seem to be correct.

Can anyone help to clear this up!!!

Thanks in advance

During a club evening, the subject of pressure was brought up. Ambient and absolute that is. There was a distinct spilt in the 'discussion' and to say things got a little heated was an understatement.

It started with 'what is the water pressure at 15m', ' answer is 1.5bar' , that i managed to follow. THen it turned to atmospheric pressure, easy thats 1bar (at sea level excluding weather systems).

As i understand it, absolute pressure is 'atmospheric pressure at sea level (in this case 1bar) plus water pressure (in this case 15m which is 1.5bar) making a total of 2.5 bar.

Then ambient pressure was introduced......

It was suggested that ambient pressure was related to the medium that was being referred to. So, the 'ambient water pressure' at 15m was 1.5bar. This made sense to me as the definition of ambient pressure suggested this.

However, it was then said that this was not correct when related to diving and that ambient and absoulte pressure are the same.

Ive looked at this and they both seem to be correct.

Can anyone help to clear this up!!!

Thanks in advance