1. 1
MEASUREMENT OF FUNDAMENTAL QUANTITIES AND
UNCERTAINTY
Frafti Rejeki S*), Karnila Sari, Lismawati, Mayang Segara
Fundamental Physics Laboratory Unit Physics Department
Universitas Negeri Makassar 2015
Abstact.
Key words : accuracy, measurement device, smallest value of scale, , uncertainty
RESEARCH QUESTIONS
1. How the uses of some basic devices measurement?
2.
EXPERIMENTAL RESULTS AND DATA ANALYSIS
EXPERIMENTAL RESULTS
1. Measurement of length
NST Ruler =
batas ukur
jumlahskala
=
1 cm
10 scale
= 0.1 cm = 1 mm
∆x =
1
2
NST alat =
1
2
× NST =
1
2
× 1 mm = 0.5 mm
NST vernier calipers
39 main scale = 20 skala nonius
1 skala nonius =
39
20
mm = 1.95 mm
NST jangka sorong = 2 mm – 1.95 mm = 0.05 mm
∆x =
1
1
NST alat =
1
1
× NST =
1
1
×0.05 mm = 0.05 mm
NST micrometer =
nilai skala mendatar
jumlah skala putar
=
0,5 mm
50
= 0.01 mm
∆x =
1
2
NST alat =
1
2
× NST =
1
2
× 0.01 mm = 0.005 mm
5. 5
Diketahui :
𝑥1=|18.5 ± 0.5| mm
𝑥2=|18.5 ± 0.5| mm
𝑥3=|18.0 ± 0.5| mm
𝑥̅ =
𝑥1 + 𝑥2 + 𝑥3
3
=
18.5 + 18.5 + 18.0
3
= 18.3 𝑚𝑚
𝛿1= | 𝑥1− 𝑥̅| = |18.5 − 18.3| mm = 0.2 𝑚𝑚
𝛿2= | 𝑥2− 𝑥̅| = |18.5 − 18.3| mm = 0.2 𝑚𝑚
𝛿3= | 𝑥3− 𝑥̅| = |18.0 − 18.3| mm = 0.3 𝑚𝑚
𝛿 𝑚𝑎𝑘𝑠 = 0.3 𝑚𝑚 ⇨ 𝛥𝑥 = 0.3 𝑚𝑚
KR =
∆𝑋
𝑋
× 100% =
0,3
18,3
× 100% = 0.01% (4 AP) sehingga
HP = [ X ± 𝛥𝑋 ] = [ 18.3 ± 0.3 ] 𝑚𝑚
Ketiga nilai X yaitu 𝑥1, 𝑥2,𝑑𝑎𝑛 𝑥3 , tercakup dalam interval [ 18.3 + 0.3 ] 𝑚𝑚 sampai
[ 18.3 – 0.3] mm.
Jika 𝛥𝑋 = 𝛿 𝑟𝑎𝑡𝑎−𝑟𝑎𝑡𝑎, maka :
𝛥𝑋 =
(0.2+0.2+0.7) 𝑚𝑚
3
= 0,3 mm
Jadi, {X} = [ X ± 𝛥𝑋 ] = [18.3 ± 0.3 ] mm
Pengukuran lebar dengan menggunakan mistar
Diketahui :
𝑥1=|18.0 ± 0.5| mm
𝑥2=|18.5 ± 0.5| mm
𝑥3=|18.0 ± 0.5| mm
𝑥̅ =
18.0+ 18.5+18.0
3
mm = 18.2 𝑚𝑚
𝛿1 = |18.0 − 18.2| mm = 0.2 𝑚𝑚
𝛿2 = |18.5 − 18.2| mm = 0.3 𝑚𝑚
𝛿3 = |18.0 − 18.2| mm = 0.2 𝑚𝑚
𝛿 𝑚𝑎𝑘𝑠 = 0.3 𝑚𝑚 ⇨ 𝛥𝑥 = 0.3 𝑚𝑚 ,
𝐾𝑅 =
∆𝑋
𝑋
× 100% =
0.3
18.2
𝑚𝑚 × 100% = 0.02 (4 𝐴𝑃) sehingga :
6. 6
HP = |18.20 ± 0.30| 𝑚𝑚
Ketiga nilai X yaitu 𝑥1, 𝑥2,𝑑𝑎𝑛 𝑥3 , tercakup dalam interval [ 18.2 + 0.3 ] 𝑚𝑚 sampai
[ 18.2 – 0.3 ] mm.
Jika 𝛥𝑋 = 𝛿 𝑟𝑎𝑡𝑎−𝑟𝑎𝑡𝑎, maka :
𝛥𝑋 =
(0.2+0.3+0.3) 𝑚𝑚
3
= 0.2 mm
Jadi, {X} = [ X ± 𝛥𝑋 ] = [18.2 ± 0.2 ] mm
Pengukuran tinggi dengan menggunakan mistar
Diketahui :
𝑥1=|17.0 ± 0.5| mm
𝑥2=|17.5 ± 0.5| mm
𝑥3=|17.5 ± 0.5| mm
𝑥̅ =
17.0+ 17.5+17.5
3
mm = 17.3 𝑚𝑚
𝛿1 = |17.0 − 17.3| mm = 0.3 𝑚𝑚
𝛿2 = |17.5 − 17.3| mm = 0.2 𝑚𝑚
𝛿3 = |17.5 − 17.3| mm = 0.2 𝑚𝑚
𝛿 𝑚𝑎𝑘𝑠 = 0.3 𝑚𝑚 ⇨ 𝛥𝑥 = 0.3 𝑚𝑚 ,
𝐾𝑅 =
0.3
17.3
× 100% = 0.01 (4 𝐴𝑃)sehingga :
HP = | 𝑋 ± ∆𝑋| = |17.30 ± 0.30| 𝑚𝑚
Ketiga nilai X yaitu 𝑥1, 𝑥2,𝑑𝑎𝑛 𝑥3, tercakup dalam interval [ 17,3 + 0,3 ] 𝑚𝑚 sampai [
17,3 - 0,3 ] mm.
Jika 𝛥𝑋 = 𝛿 𝑟𝑎𝑡𝑎−𝑟𝑎𝑡𝑎, maka :
𝛥𝑋 =
(0,3+0,2+0,2) 𝑚𝑚
3
= 0,2 mm
Jadi, {X} = [ X ± 𝛥𝑋 ] = [17.3 ± 0.2 ] mm
1.2. Jangka sorong
7. 7
Pengukuran Panjang dengan menggunakan jangka sorong
Diketahui :
𝑥1=|19.10 ± 0.05| mm
𝑥2=|19.10 ± 0.05|mm
𝑥3=|19.05 ± 0.05|mm
𝑥̅ =
19.10+ 19.10+19.05
3
mm = 19.08 𝑚𝑚
𝛿1 = |19.10 − 19.08| mm = 0.02 𝑚𝑚
𝛿2 = |19.10 − 19.08| mm = 0.02 𝑚𝑚
𝛿3 = |19.05 − 19.08| mm = 0.03 𝑚𝑚
𝛿 𝑚𝑎𝑘𝑠 = 0.03 𝑚𝑚 ⇨ 𝛥𝑥 = 0.03 𝑚𝑚 ,
KR=
0.03
19.08
× 100% = 0.001% (4 𝐴𝑃), sehingga :
HP = |19.08 ± 0.03| 𝑚𝑚
Ketiga nilai X yaitu 𝑥1, 𝑥2,𝑑𝑎𝑛 𝑥3 , tercakup dalam interval [ 19,08 + 0,03 ] 𝑚𝑚 sampai
[ 19,08 - 0,03 ] mm.
Jika 𝛥𝑋 = 𝛿 𝑟𝑎𝑡𝑎−𝑟𝑎𝑡𝑎, maka :
𝛥𝑋 =
(0,02+0,02+0,03) 𝑚𝑚
3
= 0,02 mm
Jadi, {X} = [ X ± 𝛥𝑋 ] = [19,08 ± 0,02 ] mm
Pengukuran Lebar dengan menggunakan jangka sorong
Diketahui :
𝑥1=|19.05 ± 0.05| mm
𝑥2=|19.05 ± 0.05|mm
𝑥3=|19.05 ± 0.05|mm
𝑥̅ =
19,05+ 19,05+19,05
3
mm = 19.05 𝑚𝑚
𝛿1 = |19.05 − 19.05| mm = 0 𝑚𝑚
𝛿2 = |19.05 − 19.05| mm = 0 𝑚𝑚
8. 8
𝛿3 = |19.05 − 19.05| mm = 0 𝑚𝑚
𝛿 𝑚𝑎𝑘𝑠 = 0 𝑚𝑚 ⇨ 𝛥𝑥 =
1
2
𝑁𝑆𝑇 =
1
2
× 1 𝑚𝑚 = 0.5 𝑚𝑚
KR=
0.5
19.05
× 100% = 0.02 (4 AP), sehingga :
HP = |19.05 ± 0.50| 𝑚𝑚
Ketiga nilai X yaitu 𝑥1, 𝑥2,𝑑𝑎𝑛 𝑥3 , tercakup dalam interval [ 19,05 + 0,50 ] 𝑚𝑚 sampai
[ 19,05 - 0,50 ] mm.
Jika 𝛥𝑋 = 𝛿 𝑟𝑎𝑡𝑎−𝑟𝑎𝑡𝑎, maka :
𝛥𝑋 =
(0+0+0) 𝑚𝑚
3
= 0 mm
Jadi, {X} = [ X ± 𝛥𝑋 ] = [19,05 ± 0 ] mm
Pengukuran Tinggi dengan menggunakan jangka sorong
Diketahui :
𝑥1=|18.05 ± 0.05| mm
𝑥2=|18.10 ± 0.05|mm
𝑥3=|18.10 ± 0.05|mm
𝑥 =
18.05+ 18.10+18.10
3
mm = 18.08 𝑚𝑚
𝛿1 = |18.05 − 18.08| mm = 0.03 𝑚𝑚
𝛿2 = |18.10 − 18.08| mm = 0.02 𝑚𝑚
𝛿3 = |18.10 − 18.08| mm = 0.02 𝑚𝑚
𝛿 𝑚𝑎𝑘𝑠 = 0.03 𝑚𝑚 ⇨ 𝛥𝑥 = 0.03 𝑚𝑚
KR =
0.03
18.08
× 100% = 0.001 (4 𝐴𝑃) , sehingga :
HP = |18.08 ± 0.03 | 𝑚𝑚
Ketiga nilai X yaitu 𝑥1, 𝑥2,𝑑𝑎𝑛 𝑥3 , tercakup dalam interval [ 18,08 + 0,03 ] 𝑚𝑚 sampai
[ 18,08 - 0,03 ] mm.
Jika 𝛥𝑋 = 𝛿 𝑟𝑎𝑡𝑎−𝑟𝑎𝑡𝑎, maka :
𝛥𝑋 =
(0.03+0.02+0.02) 𝑚𝑚
3
= 0.02 mm
9. 9
Jadi, {X} = [ X ± 𝛥𝑋 ] = [18.08 ± 0.02 ] mm
1.3.Mikrometer sekrup
Pengukuran panjang dengan menggunakan mikrometer sekrup
Diketahui :
𝑥1=|19.430 ± 0.005| mm
𝑥2=|19.410 ± 0.005|mm
𝑥3=|19.415 ± 0.005|mm
𝑥 =
19.430+19.410+19.415
3
mm = 19.418 𝑚𝑚
𝛿1 = |19.430 − 19.418| mm = 0.012 𝑚𝑚
𝛿2 = |19.410 − 19.418| mm = 0.008 𝑚𝑚
𝛿3 = |19.415 − 19.418| mm = 0.003 𝑚𝑚
𝛿 𝑚𝑎𝑘𝑠 = 0.012 𝑚𝑚 ⇨ 𝛥𝑥 = 0.012 𝑚𝑚 , sehingga :
{X} = [ X ± 𝛥𝑋 ] = [ 19.418 ± 0.012 ] 𝑚𝑚
Ketiga nilai X yaitu 𝑥1, 𝑥2,𝑑𝑎𝑛 𝑥3 , tercakup dalam interval [ 19,418 +
0,012 ] 𝑚𝑚 sampai [ 19,418 - 0,012 ] mm.
Jika 𝛥𝑋 = 𝛿 𝑟𝑎𝑡𝑎−𝑟𝑎𝑡𝑎, maka :
𝛥𝑋 =
(0.012+0.008+0.003) 𝑚𝑚
3
= 0.007 mm
Jadi, {X} = [ X ± 𝛥𝑋 ] = [19.418 ± 0.007 ] mm
Pengukuran Lebar dengan menggunakan mikrometer sekrup
Diketahui :
𝑥1=|18.383 ± 0.005| mm
𝑥2=|18.380 ± 0.005|mm
𝑥3=|18.390 ± 0.005|mm
𝑥 =
18.383+18.380+18.390
3
mm = 18.384 𝑚𝑚
𝛿1 = |18.385 − 18.384| mm = 0.001 𝑚𝑚
𝛿2 = |18.380 − 18.384| mm = 0.004 𝑚𝑚
10. 10
𝛿3 = |18.390 − 18.384| mm = 0.006 𝑚𝑚
𝛿 𝑚𝑎𝑘𝑠 = 0.006 𝑚𝑚 ⇨ 𝛥𝑥 = 0,006 𝑚𝑚 ,
KR=
0,006
18,384
× 100% = 0,0003 (4 𝐴𝑃)sehingga :
HP = |18,38 ± 0,06 | 𝑚𝑚
Ketiga nilai X yaitu 𝑥1, 𝑥2,𝑑𝑎𝑛 𝑥3 , tercakup dalam interval [ 18,384 +
0,006 ] 𝑚𝑚 sampai [ 18,384 - 0,006 ] mm.
Jika 𝛥𝑋 = 𝛿 𝑟𝑎𝑡𝑎−𝑟𝑎𝑡𝑎, maka :
𝛥𝑋 =
(0,001+0,004+0,006) 𝑚𝑚
3
= 0,003 mm
Jadi, {X} = [ X ± 𝛥𝑋 ] = [18,384 ± 0,003 ] mm
Pengukuran Tinggi dengan menggunakan mikrometer sekrup
Diketahui :
𝑥1=|18,340 ± 0,005| mm
𝑥2=|18,335 ± 0,005|mm
𝑥3=|18,330 ± 0,005|mm
𝑥̅ =
18,340+18,335+18,330
3
mm = 18,335 𝑚𝑚
𝛿1 = |18,340 − 18,335| mm = 0,005 𝑚𝑚
𝛿2 = |18,335 − 18,335| mm = 0 𝑚𝑚
𝛿3 = |18,330 − 18,335| mm = 0,005 𝑚𝑚
𝛿 𝑚𝑎𝑘𝑠 = 0,005 𝑚𝑚 ⇨ 𝛥𝑥 = 0,005 𝑚𝑚 ,
KR=
0,005
18,335
× 100% = 0,0002 (4 𝐴𝑃) sehingga :
HP = |18,34 ± 0,05 | 𝑚𝑚
Ketiga nilai X yaitu 𝑥1, 𝑥2,𝑑𝑎𝑛 𝑥3 , tercakup dalam interval [ 18,335 +
0,005 ] 𝑚𝑚 sampai [ 18,335 - 0,005 ] mm.
Jika 𝛥𝑋 = 𝛿 𝑟𝑎𝑡𝑎−𝑟𝑎𝑡𝑎, maka :
𝛥𝑋 =
(0,005+0+0,005) 𝑚𝑚
3
= 0,003 mm
11. 11
Jadi, {X} = [ X ± 𝛥𝑋 ] = [18,335 ± 0,003 ] mm
Table 6.hasil pengukuran panjang, lebar, dan tinggi pada balok kubus
AlatUkur P (mm) L (mm) T (mm)
Mistar
|20,0 ± 0,5| |20,0 ± 0,5|
|20,0 ± 0,5|
Jangka Sorong
|20,10 ± 0,05| |20,14 ± 0,06| |20,12 ± 0,03|
Mikrometer Sekrup
|19,970
± 0,020|
|19,583
± 0,007|
|19,543
± 0,007|
Table 7. hasil pengukuran volume pada balok
Alat ukur Volume(𝒎𝒎 𝟑
)
mistar 8000 mm3
Jangka sorong
8144, 857 mm3
Micrometer
secrup
7642,730 mm3
2. BOLA
2.1.Mistar
Pengukuran diameter dengan menggunakan mistar
Diketahui : X1 = 16,0 mm
X2 = 16,0 mm
X3 = 16,0 mm
x̅ =
x1 + x2 + x3
3
=
16,0+16,0+16,0
3
= 16,0 mm
X = | 𝑥̅ ± ∆𝑥|
δ1 = |16,0 − 16,0| = 0 mm
δ2 = |16,0 − 16,0| = 0 mm
δ3 = |16,0 − 16,0| = 0 mm
Untuk ∆x = δmaks =
1
2
NST = 0,5 ,
KR=
0,5
16,0
× 100% = 0,03 (4 𝐴𝑃)maka :
12. 12
X = |16,00 ± 0,50 | mm dan rentang nilai diameter bola yaitu 15,5 mm –
16,5 mm
Pengukuran volumebola dengan menggunakan mistar
V =
4
3
𝜋𝑟3
=
4
3
3,14 (
1
2
. 𝑑)3
=
4
3
3,14 (8)3
= 2143,57 mm3
2.2.Jangka sorong
Pengukuran diameter dengan menggunakan jangka sorong
Diketahui : X1 = 14,60 mm
X2 = 14,40 mm
X3 = 14,65 mm
x̅ =
x1 + x2 + x3
3
=
14,60 + 14,40 + 14,65
3
= 14,55 mm
X = | 𝑥̅ ± ∆𝑥|
δ1 = |14,55 − 14,60| = 0,05 mm
δ2 = |14,55 − 14,40| = 0,15 mm
δ3 = |14,55 − 14,65| = 0,10 mm
Untuk ∆x = δmaks = 0,15 , maka :
X = |14,55 ± 0,15 | mm dan rentang nilai diameter bola yaitu 14,40 mm – 14,60
mm
Pengukuran volume dengan menggunakan jangka sorong
V =
4
3
𝜋𝑟3
=
4
3
3,14 (
1
2
. 𝑑)3
=
4
3
3,14 (7,275)3
= 1608,68 mm3
2.3.Mikrometer sekrup
Pengukuran diameter dengan menggunakan mikrometer sekrup
Diketahui : X1 = 15,880 mm
13. 13
X2 = 15,600 mm
X3 = 15,870 mm
x̅ =
x1 + x2 + x3
3
=
15,880 + 15,600 + 15,870
3
= 15,783 mm
X = | 𝑥̅ ± ∆𝑥|
δ1 = |15,783 − 15,880| = 0,097 mm
δ2 = |15,783 − 15,600| = 0,183 mm
δ3 = |15,783 − 15,870| = 0,087 mm
Untuk ∆x = δmaks = 0,183 , maka :
X = |15,783 ± 0,183 | mm dan rentang nilai diameter bola yaitu 15,600
mm – 15,966 mm
Pengukuran volume dengan menggunakan mikrometer sekrup
V =
4
3
𝜋𝑟3
=
4
3
3,14 (
1
2
. 𝑑)3
=
4
3
3,14 (7,89)3
= 2056,360 mm3
Table 8. hasil pengukuran diameter pada bola
No Alat Ukur Diameter (Mm)
1.
Mistar |16,0 ± 0,5|
2.
Jangka Sorong |14,55 ± 0,15|
3.
Micrometer Sekrup |15,783 ± 0,183|
Table 9. hasil pengukuran volume pada bola
no Alat ukur Volume (𝒎𝒎 𝟑)
1
Mistar 2143,57
2
Jangka Sorong 1608,68
3
Micrometer Sekrup 2056,360
14. 14
B. Pengukuran massa
1. Balok
pengukuran massa dengan menggunakan neraca ohauss 2610 gram
Diketahui :
m1 = 62,40 gram
m2 = 62,20 gram
m3 = 62,40 gram
𝑚̅ =
m1+m2+m3
3
=
62,40+62,20+62,40
3
= 62,33 gram
m = |𝑚̅ ± ∆𝑚|
𝛿1 = |𝑚̅ − 𝑚1| = |62,33 – 62,40 | gram = 0,07 gram
𝛿2 = |𝑚̅ − 𝑚2| = |62,33 – 62,20 | gram = 0,13 gram
𝛿3 = |𝑚̅ − 𝑚3| = |62,33 – 62,40 | gram = 0,07 gram
untuk ∆𝑚 = 𝛿max= 0,13 gram, maka :
m = |62,33 ± 0,13 | gram ,dan rentang nilai massa balok yaitu 62,20 gram –
62,46 gram .
pengukuran massa dengan menggunakan neraca ohauss 311 gram
Diketahui :
m1 = 62,410 gram
m2 = 62,420 gram
m3 = 62,380 gram
𝑚̅ =
m1+m2+m3
3
=
62 ,410+62,420 +62,380
3
= 62,403 gram
m = |𝑚̅ ± ∆𝑚|
𝛿1 = |𝑚̅ − 𝑚1| = |62,403 – 62,410 | gram = 0,007 gram
𝛿2 = |𝑚̅ − 𝑚2| = |62,403 – 62,420 | gram = 0,017 gram
𝛿3 = |𝑚̅ − 𝑚3| = |62,403 – 62,380 | gram = 0,023 gram
untuk ∆𝑚 = 𝛿max= 0,023 gram, maka :
m = |62,403 ± 0,023 | gram ,dan rentang nilai massa balok yaitu 62,380 gram –
62,426 gram .
pengukuran massa dengan menggunakan neraca ohauss 310 gram
Diketahui : m1 = 62,24 gram
m2 = 62,20 gram
m3 = 62,23 gram
𝑚̅ =
m1+m2+m3
3
=
62,24+62,20+62,23
3
= 62,22 gram
m = |𝑚̅ ± ∆𝑚|
15. 15
𝛿1 = |𝑚̅ − 𝑚1| = |62,22 – 62,24 | gram = 0,02 gram
𝛿2 = |𝑚̅ − 𝑚2| = |62,22 – 62,20 | gram = 0,02 gram
𝛿3 = |𝑚̅ − 𝑚3| = |62,22 – 62,23 | gram = 0,01 gram
untuk ∆𝑚 = 𝛿max= 0,02 gram, maka :
m = |62,22 ± 0,02 | gram ,dan rentang nilai massa balok yaitu 62,20 gram
– 62,24 gram .
2. Bola
pengukuran massa dengan menggunakan neraca ohauss 2610 gram
Diketahui :
m1 = 5,90 gram
m2 = 5,90 gr
m3 = 5,80 gram
𝑚̅ =
m1+m2+m3
3
=
5,90+5,90+5,80
3
= 5,86 gram
m = |𝑚̅ ± ∆𝑚|
𝛿1 = |𝑚̅ − 𝑚1| = |5,86 – 5,90 | gram = 0,04 gram
𝛿2 = |𝑚̅ − 𝑚2| = |5,86 – 5,90 | gram = 0,04 gram
𝛿3 = |𝑚̅ − 𝑚3| = |5,86 – 5,80 | gram = 0,06 gram
untuk ∆𝑚 = 𝛿max= 0,06 gram, maka
m = |5,86 ± 0,06 | gram ,dan rentang nilai massa balok yaitu 5,80 gram – 5,92
gram .
pengukuran massa dengan menggunakan neraca ohauss 311 gram
Diketahui :
m1 = 5,810 gram
m2 = 5,800 gram
m3 = 5,800 gram
𝑚̅ =
m1+m2+m3
3
=
5,810+5,800+5,800
3
= 5,803 gram
m = |𝑚̅ ± ∆𝑚|
𝛿1 = |𝑚̅ − 𝑚1| = |5,803 – 5,810 | gram = 0,007 gram
𝛿2 = |𝑚̅ − 𝑚2| = |5,803 – 5,800 | gram = 0,003 gram
𝛿3 = |𝑚̅ − 𝑚3| = |5,803 – 5,800 | gram = 0,003 gram
untuk ∆𝑚 = 𝛿max= 0,007 gram, maka :
m = |5,803 ± 0,007 | gram ,dan rentang nilai massa balok yaitu 5,796 gram –
5,810 gram .