2006-11-28 13:41:26 · 12 answers · asked by Anonymous in Science & Mathematics ➔ Weather
sundial?
2006-11-28 13:42:57 · answer #1 · answered by DeAd DiScO 4 · 1⤊ 1⤋
Excellent question. These days the equipment that is used to do the job is called a pyranometer. The pyranometer actually collects information about the 'amount' of solar energy reaching the ground (regardless of clouds etc), but it can be set with threshold limits to indicate sunrise/sunset and cloud-cover. If you are a tourist you are interested in cloud cover (even though you'll get a tan under light clouds). For just about every other application (crops, solar energy etc) the figures that the modern instrument provides on the 'amount' of energy reaching the ground are more useful - and those are the figures that meterologists would rather have us use..
The actual duration of 'daylight' (between sunrise and sunset) can be calculated mathematically for any point on the earth's surface. A link to a website that will do that for you is listed below. Since those calculations have been available for a long time (before the internet), the instruments designed to measure 'hours of daylight' have always been primarilly interested in 'interuptions' to daylight posed by clouds. Cloud cover can now be measured a lot more accurately by radar and satellites.
2006-11-28 22:41:05 · answer #2 · answered by nandadevi9 3 · 0⤊ 0⤋
Hi. A photometer? : http://www.answers.com/main/ntquery?s=photometer&gwp=16
2006-11-28 21:44:26 · answer #3 · answered by Cirric 7 · 1⤊ 0⤋
If you're measuring hours, I'd call it a clock.
2006-11-28 21:44:23 · answer #4 · answered by BB 3 · 0⤊ 0⤋
a sundial or an egg timer
2006-11-28 21:43:26 · answer #5 · answered by Pius Thicknesse 4 · 1⤊ 1⤋
A clock?
2006-11-28 21:43:46 · answer #6 · answered by UNI Panther 3 · 0⤊ 1⤋
hours-clock
sun-sundial
hours-watch!
These are my guesses!I'm not 100% sure!
2006-11-28 21:46:02 · answer #7 · answered by rena 2 · 0⤊ 0⤋
sundial
2006-11-28 21:44:08 · answer #8 · answered by lalunamel 2 · 0⤊ 0⤋
um, a clock?
2006-11-28 21:44:09 · answer #9 · answered by armywifehaney 2 · 0⤊ 0⤋
I call it a WATCH.
But hey, that's just me!
:)
2006-11-28 21:44:05 · answer #10 · answered by Boodie 5 · 0⤊ 0⤋
my eyes
2006-11-28 21:55:37 · answer #11 · answered by Aaron 3 · 0⤊ 0⤋