This topic covers the part of bio instruments (centrifuge) and studies the effect of g force.

1. INTER-COLLEGIATE SEMINAR COMPETITION
TOPIC : CENTRIFUGE MEASUREMENT
PRESENTED BY: TANISHA SHUKLA
BSc III YEAR
SHIVAJI SCIENCE COLLEGE, NAGPUR

2. SCHEMA
 What is Centrifuge ?
 History
 Principle & Structure
 Types of Centrifuge
 Mathematical Treatment(RCF or g – force)
 Sedimentation rate
 Uses
 A way forward
 Summary

3. What is centrifuge?
An apparatus that rotate at high speed and separates
heterogeneous mixtures of solid and liquid of different
density by centrifugation.
Centrifugation
Centrifugation is a mechanical process which involves the use
of the centrifugal force to separate particles from a solution .
The denser components of the mixture migrate away from
the axis of the centrifuge, while the less dense components of
the mixture migrate towards the axis.

4. Centripetal and Centrifugal Force
Centripetal force is the component of force
acting on an object in curvilinear motion which is
directed towards the axis of rotation or centre
of curvature.
Centrifugal force is a pseudo force in a
circular motion which acts along the radius
and is directed away from the centre of the
circle.

5. History
In 1864, Antonin Prandtl proposed the idea of a
dairy centrifuge to separate cream from milk. The
idea was subsequently put into practice by his
brother, Alexander Prandtl, who made
improvements to his brother's design, and
exhibited a working butterfat extraction machine
in 1875

6. Principle of Centrifuge Measurement
The centrifuge consist of motor and rotor
 The sample to be separated is placed on the rotor and the motor makes the
rotor spin
The spinning produces a force called centrifugal force this forces causes the
substances to move away from the axis more rapidly

7. Structure of Centrifuge
The centrifuge consist of:
•Motor
•Rotor
•Sample Holders
There are two types of angle holders
•Angle type &
•Swing Bucket type

8. There are two types of angle holders
•Angle type &
•Swing Bucket type
Angle type
Swing – bucket type

9. Types of Centrifuge
• Low speed centrifuge
• High speed centrifuge
• Ultra centrifuge
• Differential centrifuge
Low speed centrifuges
• It reaches speeds between 4000-5000 rpm.
High speed centrifuges
•It reaches speeds between 25,000 rpm
Ultra speed centrifuges
•It reaches speeds between 60,000 rpm
Uses: They are used for general laboratory applications, such as separating large particles such
as cells, separating sera, plasma, urine, sperm, among others.

10. What is Relative Centrifugal Force?
The relative centrifugal force (RCF) or the g force is the radial force generated by the
spinning rotor as expressed relative to the earth's gravitational force.
F=(ω^2)r
where , ω= 2П * rpm rotation per seconds
60
RCF= (2П * rpm )^2 x r
60
hence, RCF = (RPM)2 × 1.118 × 10-5 × r

11. Sedimentation rate
The rate of movement of particles in a centrifugal
field is called sedimentation rate.
Principle :
The particles sediment because of gravitational pull ,
spinning increases gravitational pull.
Pellet: The sedimented particle is called pellet.
Supernatant: The solution above pellet is called supernatant.

12. The rate of sedimentation depends on:
1. Density of particle
2. Size of particle
3. Viscosity of medium
4. Gravitational pull

13. Applications of Centrifuge

14. A WayForward ( Gravity Simulation)
Gravity offload system works by
using overhead crane type devices
to offload the weight of human or
equipment to simulate zero gravity.
This can be achieved by centrifugal
effect caused by centripetal force of
floor of a rotating structure pushing
up on the person.

15. Centrifuges are very important devices that help us in our day to day lives
as they can be used in various walks of life.
 Ranging from laboratories, pharmaceuticals, biology and chemical
technology experiments, mining, and industrial processes.
These centrifuges, though important, do come in with a notable number
of drawbacks that need to be considered.
They have a wide range of specifications that need to be considered before
acquiring one.
SUMMARY

16. Thank You!