Cumulus Support

Hi one more question please

the local airport weather station (if i am allowed to add links i can do it) as example reporting pressure 1016hpa and is build right next of the sea so really almost by the sea level

another weather station at farer location (installed) in a mountain 600 meters high is reporting the same pressure of 1016 (not sure if he just copied the local airport measurement)

How ever i have a casio protrek series with a barometer (costing around 200 quids, i know price does not matter some times but does not look cheapy from a tener)

I am going to the local airport and calibrate the pressure to 1016 with my casio ... i know when i was in UK because i was watching the nearby stations with it ... so is kind of trusty reporting always what i have set it with the previous local stations

After set the casio with the local airport, i am coming to the place where i will install the new weather station from maplin at 170 metres about high (village in a small mountain) and the casio is reporting 1000hpa ... 16 less

which is the correct setting to set the professional barometer ? confusing here ... either the guy at 615 meters with the station is right (really his pressure should report much lower than 1000 hpa at this high) or either i am wrong to set mine at 1000? (which is what the casio reporting in the location where will install my new station)

any advice is helpful & thank you one more time
EDIT

note this done it in a sunny day where both place no wind or barometric pressure around the area was happening (was a calm & sunny day all around the island)

You need to set the relative pressure on your console to sea-level pressure, i.e. when the airport is showing 1016, your relative pressure should also be 1016. Just as the station at 615m is doing.

thanks for respond & your help, as i am new have some more questions please ...

isn't really what i need to read the local real pressure? isn't this the most important? or is any international standard to display relative and not absolute ... in other words will be illegal if i display absolute pressure? (don't mean i will do is just a question for my knowledge)

based on this of the user guide

Relative barometric pressure, corrected to sea-level. To compare
pressure conditions from one location to another, meteorologists correct
pressure to sea-level conditions. Because the air pressure decreases as
you rise in altitude, the sea-level corrected pressure (the pressure your
location would be at if located at sea-level) is generally higher than your
measured pressure

also can i try:
in a sunny calm day take a boat and go maybe 200-300 meters away from land (by the sea level where the boat will be) ... can i set the casio to sea level 14hpa and then go at my future station and add whatever the value will be up there?

is this correct? or wrong? because my English is not perfect maybe i did not understand well the user guide?

You should be displaying sea-level pressure. Cumulus will always do this for you if you set your station's relative pressure correctly, i.e. to the same as the airport.