MEASUREMENTS

MEASUREMENTS

Vernier Calipers

The Functions :

Vernier caliper is used to measure the diameter of the inside and outside of an object and measuring the depth with measurement a maximum of 20 cm.

It consists of a main scale and a vernier scale.

Accuracy :

Accuracy of 0.1 mm or 0.01 cm

Parts of vernier caliper :

 Figure 2.1. A picture of a vernier calipers. The outside jaws are used to measure the length of a solid or the diameter of sphere. The inside jaws are used to measure the inner diamater of a tube.

 

Reading of scales the vernier calipers :

 a. Look at the numbers on Main Scale (MS) before the zero Nonius 

     scale (NS)

              In the example problems: SU = 5.8 cm 

b. Look at the numbers on Nonius Scale (NS), which coincide

  In the example problems: SN = 5 x 0,01 cm = 0.05 cm

             (ingat angka yang berhimpit dikalikan dengan accuracy) 

c. Actually value (AV) in the measurement

AV = MS + NS = 5.8 cm + 0.05 cm = 5.85 cm

(Remember to add up the units must be the same)

 Micrometer Screw

We can use a micrometer to measure very small lengths to an accuracy of 0.01 mm. It consists of a main scale and a nonius scale like vernier caliper.

Micrometer is used to measure the diameter of fine wire, the thickness of paper and other very short lengths with measurement a maximum of 25 mm.

 Figure 2.2. A picture of a micrometer screw gauge. It has two scales: the main scale on the sleeve and the circular scale on the thimble. Turning the thimble and moving the circular scale up or down one division, will cause the spindle to move 0.01 mm or 0.001 cm horizontally.

 

Reading of scales the micrometer screw :

 

1. Look at the numbers on the Main Scale (MS) before numbers Nonius scale (before the vertical line)

That look is the number of 2.5 mm the value of MS = 2.5 mm

2. Look at the numbers Nonius scale (NS), which coincide (garis MS dan NS berhimpit). Which coincide is number 20,

NS = 20 x 0.01 mm = 0.20 mm (remember the figures coincides with the precision of a micrometer multiplied = 0.01 mm)

3. Actually Value (AV) in the measurement

AV = MS + NS = 2.5 mm + 0.20 mm

                                       = 2.70 mm

Measurement of Volume

1. Regular Volume

The volume of an object with a regular shape can be calculated after measuring the lengths of its sides, its diameter, or other lengths. Then the appropriate formulae (as described below) for the volumes are used. The SI units for volume is cubic metres (m³).

Volume of a cube = length³

Volume of a rectangular block = length × width × height

Volume of a sphere = 4/3  r³ (where r is the radius)

Volume of a cylinder =  r²h (where r is the radius and h is the height)

Volume can be expressed as mm³, cm³ or m³. Sometimes you will see litres being used.

1 litre (l) is equivalent to 1000 cm³.

2. Irregular Volume

The volume of an object with an irregular shape can be measured by using a measuring cylinder or displacement can. Two figures below are shown methods to measure the volume of an irregular shape object.

This Material can be downloaded in here 

Individual Task download in here  

 

Biar kalian lebih memahami materi diatas, coba kalian lihat video berikut :

Besok kalo ada pertemuan lagi kita praktekkan!!

Vernier Caliper

 

Micrometer Screw 
Graduated Cylinder

Triple-beam Balance