The relationship between revolutions per minute (RPM) and relative centrifugal force (xg) is:

g = (1.118 × 10-5) R S2

where g is the relative centrifugal force, R is the radius of the rotor in centimeters, and S is the speed of the centrifuge in

revolutions per minute.

You can use this for any centrifuge, just measure the radius of the rotor from the center to outer edge

Unfortunately g's are a function of rpms and the radius from the axis of rotation, so there isn't a direct conversion that will work for every centrifuge since the radius will vary depending on the model of centrifuge. However, you may be able to find your centrifuge's rotor here and just use their calculator.

http://www.endmemo.com/bio/grpm.php

G force depends on rpm and the radius. You can use the following equation for the conversion : g Force (RCF) = (rpm)2 × 1.118 × 10-5 × r   (where r is the rotational radius in centimeter)

Thanks. In the converter, do we use the smallest or largest diameter to calculate ? As the converter has maximum and minimum radius

Rmax will give you the g force at the bottom of the tube, Rmin will give you the g force at the top of the tube - usually the g force quoted in a protocol is the R max value, but it may be the Raverage.

There should be a conversion table in the manual of the rotor (If it is not possible to change the display of the centrifuge. Good luck; Helge

The relationship between revolutions per minute (RPM) and relative centrifugal force (xg) is:

g = (1.118 × 10-5) R S2

where g is the relative centrifugal force, R is the radius of the rotor in centimeters, and S is the speed of the centrifuge in

revolutions per minute.

You can use this for any centrifuge, just measure the radius of the rotor from the center to outer edge

An important note to consider: Radius should be calculated as the distance from the center of the rotor to your sample! Calculating the radius as the distance from the center to the outer edge is an error.

just put the values and get the results

VERY VALUABLE INFORMATION PUT BY AUTHORS.....I THINK THIS WAS THE REASON THAT WHAT I READ FOR PRF PREPARATION THAT 3000 RPM FOR 10 MINUTES IS ENOUGH.....BUT I REQUIRE 30 MINUTES, BECAUSE PROBABLY I USE CENTRIFUGE MACHINE WITH DIFFERENT RADIUS

RCF (or g) = 1.12 x Radius x (rpm/1000)^2

http://www.answers.com/Q/Difference_between_g_and_RPM_in_centrifugation#slide1

Hello

The relationship between revolutions per minute (RPM) and relative centrifugal force (xg) is: g = (1.118 × 10-5) R S2 where g is the relative centrifugal force, R is the radius of the rotor in centimeters, and S is the speed of the centrifuge in revolutions per minute.

You can use this for any centrifuge, just measure the radius of the rotor from the center to outer edge .

see this online tool : http://www.labtools.us/centrifugation-speed-rpm-to-g-conversion/

Good Luck

There are two formulas here

Which one is correct and what about k factor and sedimentation

Hello,

you can see the attached file.

The g force of centrifuge can be calculated using this formula:

g = 1.118 x r x rpm² or

rpm = Square root {g /(1.118 x r)}

r = radius of centrifuge in mm; rpm = rotations per minute/1000

e.g.1

r = 100 mm; rpm2 = 9 (3000 rotations per minute/1000)

g = 1.118 x 100 x 9 = 1006 g

e.g.2

r = 100 mm; g = 1200 g

rpm = SQR {1200/(1.118 x 100)} x 1000 = 3276 rotations per minute

im also struggling to convert rpm to g

12,000 xg how many rpm

This is the correct formula:

g = (1.118 x 10-5) R S2

where S is the speed of the centrifuge (RPM), g is the relative centrifugal force, R is the radius of the rotor {distance from the centre of rotor to the sample (in cm)}.

g = (1.118 × 10-5) R S2

where g is the relative centrifugal force, R is the radius of the rotor in centimeters, and S is the speed of the centrifuge in revolutions per minute. Radius should be calculated as the distance from the center of the rotor to your sample (not to outer edge)

this is a document from Thermo scientific where they make a table with differents values of g R and rpm

The relationship between revolutions per minute (RPM) and relative centrifugal force (xg) is: g = (1.118 × 10-5) R S2

where g is the relative centrifugal force, R is the radius of the rotor in centimeters, and S is the speed of the centrifuge in revolutions per minute. You can use this for any centrifuge, just measure the radius of the rotor from the center to outer edge

t agree with Akash Sabarwal

The whole matter can be resolved by simple basics from any chapter "MECHANICS" from a school PHYSICS book:

http://www.youscreen.de/axvnyceye31.jpg

Keep in mind that:

Firstly: g is lower at the äquator (g=9.78) and highest at the poles (g=9.84) as earth is rotating too

Secondly: effective centrifugal acceleration differs WITHIN the vials rotating!! Filled to the very top the effective radius is remarkably reduced, so is the x times g acceleration too: half the radius reduces centrifuge acceleration that may result in tinier pellets, reduced efficiency!! Use many vials with less filling in opposite centrifuges positions. Always BALANCE ROTOR in opposite places, avoid severe accidents!!! 12.000 xg will result in severe damage to lab and people in range! 1ml+1g vial behaves like a 24 kg mass approachig you at the respective tangential velocity (cannon ball!) Consider of broken rotors spindle too....

Thirdly: g is no force but an acceleration! When multiplied by mass giving you a force in Newton.

If still in doubt ask any 15 to 16 year old pupil, they had in Physics, a nice portion of delicious ice-cream might help to make them remember and willing to explain the respective formulas.

In case of no sweets available, watch this lecture(s):

https://www.youtube.com/watch?v=WQ9AH2S8B6Y

g = (1.118 × 10-5) R S2

where g is the relative centrifugal force, R is the radius of the rotor in centimeters, and S is the speed of the centrifuge in revolutions per minute. Radius should be calculated as the distance from the center of the rotor to your sample (not to outer edge)

http://insilico.ehu.es/mini_tools/rcf_rpm.php

Direct conversion