# Temperature mixing formula

(Difference between revisions)
 Revision as of 05:30, 25 September 2008 (view source) (New page: This page is to help calculating the amount of one liquid you need to add to another to get a special temperature. This is often usefull if you perform a temperature shift for example with...)← Previous diff Revision as of 05:46, 25 September 2008 (view source)Next diff → Line 1: Line 1: This page is to help calculating the amount of one liquid you need to add to another to get a special temperature. This is often usefull if you perform a temperature shift for example with cultures of organisms that carry a temperature sensitive mutant. This page is to help calculating the amount of one liquid you need to add to another to get a special temperature. This is often usefull if you perform a temperature shift for example with cultures of organisms that carry a temperature sensitive mutant. - + ==Formula== Here is a form of Richmann’s calorimetric mixing formula: Here is a form of Richmann’s calorimetric mixing formula: - $m_{1}= \frac{m_{2}\cdot T_{2}+ T_{m}\cdot m_{2}}{T_{m}-T_{1}}$ + + $m_{1}= \frac{m_{2}\cdot T_{2}- T_{m}\cdot m_{2}}{T_{m}-T_{1}}$ + + + *m1 is the mass of the liquid you want to add + *m2 is the mass of the liquid that you have + *T1 is the temperature of the liquid you want to add + *T2 is the temperature of the liquid you have + *Tm is the temperature that you want to have after mixing + + + ==Example== + + Suppose you have a 100 ml culture at 39°C and want to shift it to 30°C with the help of 4°C cold fresh medium. + *m2=100 + *T1=4 + *T2=39 + *Tm=30 + + Than the formula is: + + + $m_{1}= \frac{100\cdot 39- 30\cdot 100}{30-4}$ + + + That means that m1 is 34.6, so if you add 34.6 ml of 4°C cold fresh medium to your culture it will be 30°C warm.

## Revision as of 05:46, 25 September 2008

This page is to help calculating the amount of one liquid you need to add to another to get a special temperature. This is often usefull if you perform a temperature shift for example with cultures of organisms that carry a temperature sensitive mutant.

## Formula

Here is a form of Richmann’s calorimetric mixing formula:

$m_{1}= \frac{m_{2}\cdot T_{2}- T_{m}\cdot m_{2}}{T_{m}-T_{1}}$

• m1 is the mass of the liquid you want to add
• m2 is the mass of the liquid that you have
• T1 is the temperature of the liquid you want to add
• T2 is the temperature of the liquid you have
• Tm is the temperature that you want to have after mixing

## Example

Suppose you have a 100 ml culture at 39°C and want to shift it to 30°C with the help of 4°C cold fresh medium.

• m2=100
• T1=4
• T2=39
• Tm=30

Than the formula is:

$m_{1}= \frac{100\cdot 39- 30\cdot 100}{30-4}$

That means that m1 is 34.6, so if you add 34.6 ml of 4°C cold fresh medium to your culture it will be 30°C warm.