Extreme winter of 1898-99

[jmundie]

Do digital barometers not also use mercury?

My thought would be, rather than one measurement being less accurate than the other, is the sparsity of data points available. I would imagine that the pressure readings on those storms probably come in on the low side, given they didn't have a good way to tell where the exact center of circulation was. Not like they had satellites, and weather stations in every teeny tiny town that could easily report their findings. Telegraph was still relatively new technology then, remember. And I imagine with a storm that size with that kind of cold air, communication pretty much ground to a halt in the still rural south.

[toastido]

Do digital barometers not also use mercury?

No.  Generally digital barometers use electrical charges to determine the density of the air, and thus, the pressure. 

[Cyclonicjunkie]

Do digital barometers not also use mercury?

My thought would be, rather than one measurement being less accurate than the other, is the sparsity of data points available. I would imagine that the pressure readings on those storms probably come in on the low side, given they didn't have a good way to tell where the exact center of circulation was. Not like they had satellites, and weather stations in every teeny tiny town that could easily report their findings. Telegraph was still relatively new technology then, remember. And I imagine with a storm that size with that kind of cold air, communication pretty much ground to a halt in the still rural south.

Very good and very valid points Mundie.

[John1122]

I would say a lot of those readings came from ships. Ships have had barometers for hundreds of years and were basically the way to report/forecast weather coming in from the oceans up until the satellite era.

As for which type of barometer is more accurate, most things I've read say the old mercury ones are. The National Physical Laboratory which is dedicated to exact scientific measurements says their primary barometer is a mercury barometer. Although they say now technology has advanced to where the difference is minimal.

[Cyclonicjunkie]

The digital output on the new ones are more accurate by nature...its just like anything else digital Vs Analog. There is less human error in reading a digital display on a watch than there is reading an old analog stop watch or something like that... A digital one displays it right on the screen for you..there is no counting/estimating/guestimating involved. The way they are designed just provides a more accurate reading.

Then you have to go into all the mechanics (Moving parts) of an old barometer...they could very well go bad due to friction and such...but a digital one dont have moving parts (to my knowledge).

The new ones are definately more accurate by design...how much more...I do not know.

[John1122]

Well I guess the NPL will disagree with you on that one Toot.

They say the mercury based ones are more accurate, so for official measurements that is what they use.