penjelasan inframerah ppt

5/24/2018 penjelasan inframerah ppt

1/5

Discovery

Herschel directed sunlight through a glass prism to create a spectrum - the "rainbow"

created when light is divided into its colors - and measured the temperature of each color.

He used three thermometers with blackened bulbs (to better absorb the heat) and placed

one bulb in each color while the other two were placed beyond the spectrum as controlsamples. As he measured the temperatures of the violet, blue, green, yellow, orange and red

light, he noticed that all of the colors had temperatures higher than the controls and that the

temperature of the colors increased from the violet to the red part of the spectrum. After

noticing this pattern, Herschel decided to measure the temperature ust beyondthe red

portion of the spectrum in a region apparently devoid of sunlight. !o his surprise, he found

that this region had the highest temperature of all. Herschel performed further eperiments

on what he called the "calorific rays" that eisted beyond the red part of the spectrum and

found that they were reflected, refracted, absorbed and transmitted ust like visible light.

#hat $ir #illiam had discovered was a form of light (or radiation) beyond red light. !hese

"calorific rays" were later renamed infrared rays or infrared radiation (the prefi infra means%below&). Herschel&s eperiment was important not only because it led to the discovery of

infrared, but also because it was the first time that someone showed that there were forms of

light that we cannot see with our eyes.

Sir Frederick William Herschels Process of Discovery

!hese were used by Hershel in his first eperiments with the solar spectrum beyond our

vision. !he mirror was slowly rotated to keep a beam of sunlight in a constant direction while

the prism split it into different colors. Herschel found that the highest temperature was ust

beyond the red part of the spectrum, the area we now know as the &infrared&.

History

1878:!he bolometer is developed by $amuel 'ierpoint angley. !his instrument is an

electrical detector of radiant heat which can detect a broader range of infrared wavelengths.

angley&s bolometer is sensitive to differences in temperature of one hundred-thousandth of

a degree elsius.

1948:*nfrared studies of the +oon reveal that its surface is covered with a fine powder more

than years before the moon landings.

1961:!he germanium bolometer is developed by rank ow. !his instrument is hundreds of

times more sensitive than previous detectors and capable of detecting far-infrared radiation.

Todays Usage

/octors use infrared lamps to treat skin diseases and relieve the pain of sore muscles. *n

these treatments, the infrared rays pass through the patient&s skin and produce heat.

$cientific advances pertaining to infrared have allowed buildings to keep cool even in the

summer. 0old transparent films in the windows of large office buildings reflect infrared and

help to keep temperatures cool

'hotographers use film that is sensitive to infrared rays to take pictures in places wherethere is no visible light. 1urglar alarms also use infrared.


2/5

*nfrared is used etensively in specially-designed ovens for drying painted and enameled

surfaces, leather, metals, papers and tetiles.

Properties

*nfrared rays travel at the speed of light like all electromagnetic waves.

*nfrared waves have wavelengths longer than visible and shorter than microwaves, and have

fre2uencies which are lower than visible and higher than microwaves.

*nfrared is broken into three categories3 near, mid and far-infrared. 4ear-infrared refers to the

part of the infrared spectrum that is closest to visible light and far-infrared refers to the part

that is closer to the microwave region. +id-infrared is the region between these two.

The Elegtromagetic !pectr"m

!he top picture shows the wavelengths of waves. *nfrared falls right in between visible light

and radio waves. !he infrared wavelength is the si5e of a pinhead on the bottom picture.

#$rared %adiatio

!he primary source of infrared radiation is heat or thermal radiation. !his is the radiation

produced by the motion of atoms and molecules in an obect. !he higher the temperature,

the more the atoms and molecules move and the more infrared radiation they produce. Any

obect which has a temperature i.e. anything above absolute 5ero (-678.9: degrees

ahrenheit or -:;.s no movement of atoms, there is no infrared

Dagers

Although infrared is important, it also has some dangers associated with it. !he thin

gold films on space crafts reflect infrared rays from the sun which can harm both

people and the e2uipment on the craft.

#ear sunglasses and sunscreen for protection

/efinition

*nfrared (*?) light is electromagnetic radiation with longer wavelengths than those of visible

light, etending from the nominal red edge of the visible spectrum at : nanometres (nm) to

< mm.
http://coolcosmos.ipac.caltech.edu/cosmic_classroom/ir_tutorial/irregions.htmlhttp://coolcosmos.ipac.caltech.edu/cosmic_classroom/cosmic_reference/heat_temp.htmlhttp://coolcosmos.ipac.caltech.edu/cosmic_classroom/ir_tutorial/irregions.htmlhttp://coolcosmos.ipac.caltech.edu/cosmic_classroom/cosmic_reference/heat_temp.html


3/5

penemuan

Herschel diarahkan sinar matahari melalui prisma kaca untuk menciptakan spektrum - yang

" pelangi " yang diciptakan ketika cahaya dibagi menadi warna - dan mengukur suhu setiap

warna . /ia menggunakan tiga termometer dengan lampu menghitam ( untuk lebihmenyerap panas ) dan ditempatkan satu lampu di setiap warna sementara dua lainnya

ditempatkan di luar spektrum sebagai sampel kontrol . $aat ia mengukur suhu violet , biru,

kuning , hiau , oranye dan merah , ia melihat bahwa semua warna memiliki suhu lebih tinggi

dari kontrol dan bahwa suhu warna meningkat dari ungu ke bagian merah dari spektrum .

$etelah memperhatikan pola ini , Herschel memutuskan untuk mengukur suhu hanya di luar

bagian merah spektrum di daerah tampaknya tanpa sinar matahari. @ang mengeutkan, ia

menemukan bahwa daerah ini memiliki suhu tertinggi dari semua . Herschel melakukan

eksperimen lebih lanut tentang apa yang disebut " sinar kalori " yang ada di luar bagian

merah spektrum dan menemukan bahwa mereka tercermin , dibiaskan , diserap dan

ditransmisikan seperti cahaya tampak . Apa $ir #illiam telah menemukan adalah bentukcahaya ( atau radiasi ) di luar lampu merah . *ni " sinar kalori " yang kemudian berganti nama

menadi sinar infra merah atau radiasi inframerah ( awalan infra berarti % bawah & ) .

'ercobaan Herschel adalah penting bukan hanya karena hal itu mengarah pada penemuan

inframerah , tetapi uga karena itu adalah pertama kalinya bahwa seseorang menunukkan

bahwa ada bentuk-bentuk cahaya yang tidak bisa kita lihat dengan mata kita .

'roses $ir rederick #illiam Herschel /iscovery

*ni digunakan oleh Hershel dalam eksperimen pertamanya dengan spektrum matahari di luar

visi kami . ermin perlahan diputar untuk menaga sinar matahari di arah yang konstan

sementara prisma dibagi menadi warna yang berbeda . Herschel menemukan bahwa suhu

tertinggi hanya di luar bagian merah dari spektrum , daerah yang sekarang kita kenal

sebagai & inframerah & .

searah


4/5

dicat dan enamel permukaan , kulit , logam , kertas dan tekstil .

properti

$inar inframerah peralanan dengan kecepatan cahaya seperti semua gelombang

elektromagnetik .

0elombang inframerah memiliki panang gelombang lebih panang dari yang terlihat dan

lebih pendek dari gelombang mikro , dan memiliki frekuensi yang lebih rendah dibandingkan

terlihat dan lebih tinggi dari microwave .

*nframerah ini dibagi menadi tiga kategori 3 dekat , menengah dan auh-inframerah . /ekat-

inframerah mengacu pada bagian dari spektrum inframerah yang paling dekat dengan

cahaya tampak dan inframerah-auh mengacu ke bagian yang lebih dekat ke wilayah

microwave . +id - inframerah adalah wilayah antara kedua .

!he Blegtromagnetic $pectrum

1agian atas gambar menunukkan panang gelombang gelombang . *nframerah atuh tepat

di antara cahaya tampak dan gelombang radio . *nframerah panang gelombang adalah

ukuran kepala peniti di bagian bawah gambar .

?adiasi inframerah$umber utama radiasi inframerah radiasi panas atau termal . *ni adalah radiasi yang

dihasilkan oleh gerakan atom dan molekul dalam suatu obek . $emakin tinggi suhu ,

semakin banyak atom dan molekul bergerak dan lebih banyak radiasi inframerah yang

mereka hasilkan . $etiap obek yang memiliki suhu yaitu apa pun di atas nol mutlak ( -678,9:

deraat ahrenheit atau -:;,


5/5

=esimpulan

*nframerah termasuk bagian dari gelombang elektromagnetik. *nframerah terdapat pada

benda-benda yang mengeluarkan panas.*nframerah banyak dimanfaatkan pada bidang

industri elektronik. 1ahaya dari inframerah ialah radiasi yang dikeluarkan inframerah dapat

mengganggu kesehatan manusia.

onclusion

*nfrared are part of the electromagnetic wave and *nfrared contained in obects that emit

heat. *nfrared had been used in the electronics industry./angers of infrared radiation that is

released infrared can interfere with human health.

penjelasan inframerah ppt

Documents

Transcript of penjelasan inframerah ppt