"Martin Rowley" wrote in message
...


... try monitoring on a daily basis what you read and what the nearest
observation is at the same time - plot these out on a graph such that
you get a scatter diagram and see if you can draw a line of best fit
(might not be a straight line - might be a curve ... if as you say the
differences are greater at the 'edges' of the range).


I will do that and compare it with the station reports on the BBC site as
that is the neares I know of.

If there is no obvious clustering around a particular line, I would
suspect that the errors are random and there would be little you could
do to relate your instrument to the mslp pattern. However - see below.

Also make sure that there are no sources of heat (either radiators, or
direct sunshine) in the vicinity - the unit should be in a thermally
stable environment as far as possible.


It is situated in the screen with the thermometers and hygrometer - it
cannot get direct sun / wind etc.

I have another (old) barometer in the house which is of a less
accurate
nature, but that is reading over 1040 today (1043 on the Diplex).

... don't assume the 'old' barometer is no good! In my experience, some
of these (and we have one that is at least 70 years old) are more
accurate than the stuff you can buy today.


My fault - I meant an "old cheapie" barometer - it is too small and too
inaccurate to use for recording, but was a reasonably useful indicator.
I agree with your point re the 'good old' barometers and remember large
brass-cased examples from my childhood.


Unless you are on a North Sea oil rig as I send this (07/1100Z or midday
local), then your pressure should not be above about 1040mbar.


I was not at home at the time mentioned .... I have 1041 mb at 1430 local.

Good luck!


Thanks for your help - I shall persevere.

Gianna