PENGGUNAAN ALAT UKUR DASAR

PENGGUNAAN ALAT UKUR DASAR

I. TUJUAN

1. Mampu menggunakan alat ukur yang digunakan dalam praktikum Fisika.

2. Mengenal besar ketelitian pengukuran dari alat-alat ukur dasar.

3. Mengenal apa yang dimaksud dengan skala nonius.

II. ALAT DAN BAHAN

1. Batangan besi

4 . Jangka sorong

2. Kelereng

5. Mikrometer Skrup

3. Pengaris

III. TEORI RINGKAS

Nonius

Banyak alat ukur dilengkapi dengan nonius. Alat bantu ini membuat alat ukur berkemampuan lebih besar, karena jarak antara dua garis skala bertetangga seolah-olah menjadi lebih kecil. Biasanya pembagiuan skala utama dan nonius adalah :

Selanjutnya marilah kita lihat hasil pengukuran lain dengan alat bantu nonius tersebut seperti yang ditunjukkan pad gambar. Skala 0 pada nonius tidak berimpit dengan salah satu angka pada skala alat ukur, melainkan terletak antara kedudukan 8.4 dan 8.5. Dalam pengukuran ini kita yakin bahwa harga X yang diukur adalah lebih besar dari 8.4 tetapi lebih kecil dari 8.5. Berapakah harga X emnurut hasil pembacaan ini ? Cobalah anda perhatikan Gambar 2 lebih teliti lagi. Ternyata salah satu garis skala nonius yang berimpit dengan skala alat ukur yaitu skala ke-6 dari skala nonius. Dalam keadaan pengukuran semacam ini menunjukkan bahwa harga X yang diukur adalah 8.46.

2. Jangka Sorong

1. Jangka sorong merupakan suatu alat pengukuran yang cepat dan relatif teliti untuk mengukur diameter dalam, luar dan dalam suatu tabung, yang memiliki bentuk seperti gambar 1 di bawah ini.

Gambar 1. Jangka Sorong

3. Mikrometer SekrupMikrometer Sekrup dipergunakan untuk mengukur panjang benda yang memiliki ukuran maksimum 2,50 cm, dan bentuk mikrometer sekrup ditunjukkan pada gambar 2. Alat ukur ini mempunyai batang pengukur yang terdiri atas skala dalam milimeter, dan juga sekrup berskala satu putaran sekrup besarnya sama dengan 0.5 mm dan 0.5 mm pada skala utama dibagi menjadi 100 skala kecil yang terdapat pada sekrup.

Gambar 2. Mikrometer SekrupIV. PROSEDUR PERCOBAAN

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Data Percobaan dan Perhitungana. Jangka Sorong

NoXX2

XoX

1

2

3

4

5

a. Mikrometer Sekrup

NoXX2

XoX

1

2

3

4

5

VI. Kesimpulan...................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................

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..........................................................................................................................................................................................................9 bagian skala ukur 10 bagian skala nonius

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_1280658087.unknown

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