Converting a temerature "range"

[Iceman]

I have a problem with converting temperatures from Farenheit to Celcius.

I understand that it is usually a simple conversion, however this is different....

I'm dealing a commercial product that claims to "Increase a Plants Natural Tolerance to frost"

The claim is "increases resistance to cold injury and cold mortality by 2.2° to 9.4° Fahrenheit"

Now if you simply convert the temperatures from Farenheit to Celcius, the claim would read...

"increases resistance to cold injury and cold mortality by -16.5° to -12.5° Celcius"

This cannot be correct and makes no sense to me.

Some, tell me that it should read (in Celcius) like this....

"increases resistance to cold injury and cold mortality by 1.2° to 5.2° Celsius" which makes more sense BUT. I need to understand why and how this converison works.

Any takers ?

Thanks

 

[tkhunny]

Those are relative terperatures, not actual temperatures. Celsius degrees are bigger than Fahrenheit degrees.

Consider Freezing

0ºC and 32ºF

Consider Boiling (STP)

100ºC and 212ºF

Thus, moving from Freezing to Boiling, requires:

100ºC - 0ºC = 100ºC
212ºF - 32ºF = 180ºF

And we see that a change of 180ºF = a change of 100ºC and a ratio can be created 100/180 = 50/90 = 25/45 = 5/9. THERE is the magic number! (Let's ignore the units and just remember that it converts ChangeºF to ChangeºC)

A change of [2.2,9.4]ºF = a change of [2.2,9.4]*(5/9) ºC = [1.22,5.22]ºC