Incorrect altitude changes

Timex Helix ABT.
This watch calculates altitude by measuring air pressure and relating that value to the international standard atmosphere. 1013.25 mb = 0 metres.
The Timex ABT does not display negative altitude values. So if the measured air pressure is greater than 1013.25 mb and the altimeter is reset (select altimeter, pull out the crown 1 click and press and hold the lower left button) the watch will display LO. You can experiment with this. Wait till the barometer reads 1013 or 1012 and reset the altimeter. The watch will display zero or maybe 5 metres. Or wait till the pressure goes up to, say, 1022 and reset the altimeter. The watch will read LO again. If this happens alot, you probably live fairly close to sea level. What you can do to trick the watch is use a vacuum cleaner to raise the perceived altitude of the watch then calibrate the altimeter (pull out and rotate the crown) and change the altimeter reading to, say, 200 metres. It wont read LO then. Keep an eye on it and the atmospheric pressure. If the pressure starts to rise then adjust the altimeter accordingly. Remember this watch is designed to measure proper altitudes where the air pressure isnt likely to be as high as 1013.25. If you are mooching around near sea level the naturally changing air pressure will often make the watch read LO.
If you live up in Montana at 1500 metres (ISA standard pressure about 840 mb) all the time then the watch will always read a positive value and you can calibrate it from reference to a map or road sign etc. The atmospheric pressure will unlikely reach as high as 1013 up there and the watch wont read LO.

Erik, the altimeter uses barometric pressure to determine changes in elevation. Rule one is whenever you know the elevation for a fact, adjust it as the barometer is changing often and therefore affecting the altimeter reading. The only sure way to avoid this is use GPS. Altitude is derived from locating 3 or 4 satellites in a geo syncrohnus(SP?) orbit. Pilots always reset the altimeter before take off and you should too. Find elevations on road signs, maps, etc.

You should carefully read the manual on this watch. It is a very sophisticated instrument realitive to its cost.

The barometric pressure in the CAL mode is set to the reference sea level. The pressure that is read in the other areas is the actual or relative pressure at your location.

There are some tollerences for the accuracy of these watches. What they are excellent at is seeing the relative differences or changes. I found that when I set the reference barometric pressure (Sea Level Pressure), everything falls in to place. I found the WP4 to be accurate to within about 15 to 20 feet accuracy for altitude most of the time. It is important to periodically check the barometric pressure from the weather office if you want it to be as accurate as possible.

When hiking or out trecking, it is advisable to check the watch's altitude relative to the map that you are using, or to a known reference. Then as you travel you can check for the altitude change.

Take care that this type of watch is to be used as a quick or easy reference only. It is not certified to be used in situations where life and safety are fully dependent on the readings from this type of watch. It is a precision instrument, but not as precise as the high end professional certified types. It is best to refer to proper maps (charts), and depend on a certified mechanical compass for absolute reference.

Jerry G.

good day,
hope this link below will solve your problem.

watches

Altimeters on watches are usually based on barometric pressure, since the pressure changes all the time you generally need to adjust the altimeter to a known altitude. You can look on USGS website to find the altitude of your area, or simply type in "altitude of city, state" in a search engine.
I hope I understood your question; if not, please reply.

It sounds like IC (integrated Circuit) in your watch is mulfunctioning, but can be something else. Can't say without inspection.None of the readings mentioned by you is acceptable.
As the watch is purely microelectronic, there is nothing you can do but to take it back to the retailer and ask for repair or replacement. If your watch is just 10 days old, this must be done under warranty and at no cost to you.
Don't forget to rate, please.

Read my previous solution, please.

Don't forget that the altimeter is barometric, and therefore the altitude reading will change depending on the air pressure - i.e. the weatherman may give the 'high pressure coming through' or that there is a low pressure giving rain - to get the true altitude, you need to know the true air pressure at any given point on the earth ~(where you are) then set this as the 'normal'. you will then get the correct altitude. Don't forget that if you are in a pressurised aircraft - as in allcommercial flights, the cabin air pressure is artificially kept at appx 4000-6000ft altitude

Yes, Sir. But remember when pilots reset their altimeter with the local altitude, the pressure value matches the moment wheather pressure. It will be wrong anyway, if you reset you altitude, but the pressure readings are still wrong. Im my case it is happening. The altutide is correct but the pressure of the watch does not match the local pressure. It is 20 hpa over it. By the way, I am an airline pilot.