testing the accuracy of a thermometer in boiling water, it's important
to know the boiling point of water at your location, especially if you
live at high altitude. The boiling point of water is influenced mainly by
atmospheric pressure, and atmospheric pressure varies based on your altitude and
current weather conditions. Since weather conditions change from day to
day, it's best to determine the boiling point of
water right at the time you are about to test your thermometer.
Here's a calculator
that estimates the boiling point of water based on your current
barometric pressure in inches of
mercury (inHg) and your elevation in feet.
determine your barometric pressure, visit The Weather Channel.
your city name or ZIP code on the home page to look up your
current weather conditions.
your barometric pressure.
can also get your current pressure from The Weather Channel on
determine your elevation in the United States, try
using the USGS
Geographic Names Information System.
your city name in the "Feature Name" field.
your state from the "State or Territory" list.
Select your county from the "County" list.
"Populated Place" from the "Feature Class" list.
If your city
is found, click on it to view detailed information.
can't determine your elevation at the USGS site, or if you don't
live in the United States, use a search engine like Google
to search on the phrase
"elevation of London, England", substituting your own
city name. The elevation will often be listed with information about nearby airports or on a city's website.
Do I Have To Provide My Elevation?
The barometric pressure for
your location that is reported on the Web or on television has been
adjusted to sea level. To perform a valid boiling point calculation, you
must provide your elevation so the sea level adjustment can be "undone".
If you have a barometer at
home with a pressure reading that is not adjusted to sea level,
just enter zero in the Elevation field.