Barometer help please

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markymark2406

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• 9 Oct 2021

• #1

I’ve been given an old Barometer (pictured) I’m trying to set this up but can only find 1025mb on websites for todays pressure, how does this relate to the numbers on my barometer ?

 

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charliegolf

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• 9 Oct 2021

• #2

I suspect the numbers on the face are 'inches of mercury' an older measurement. Natch the Americans still use it widely.

Have a look...

https://www.metric-conversions.org/pressure/millibar-to-inches-of-mercury.htm

1025 is around 30 and a 1/4 inches.

 

Justin Passing

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• 9 Oct 2021

• #3

Those numbers are inches. 1000mbar is 29.53 inches of mercury.

 

Last edited: 9 Oct 2021

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RandomGrinch

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• 9 Oct 2021

• #4

As above inHg...

 

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Old Salt

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• 9 Oct 2021

• #5

Definitely inches of mercury. No pointer? The pointer is normally set by adjusting a screw at the back. Local airport, coastguard or weather station will give you an accurate measure if you ring and ask.

 

Harry Bloomfield

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• 9 Oct 2021

• #6

You may need to offset, for height above see level.

 

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RandomGrinch

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• 9 Oct 2021

• #7

Harry Bloomfield said:

You may need to offset, for height above see level.

Click to expand...

I found this on Google:

They are instructions for making the correction for height above sea level.
It might not be completely relevant to the OP's model but interesting none the less!

I especially like the part about "It is important that the barometer is hung vertically and glass tapped before reading'!