water / kerosene for proton mag

[John Smith]

I read in JA Koehler's excellent description of ppms that kerosene polarises far quicker than distilled water.


This would seem a massive advantage when considering battery power consumption.


Does anyone know the disadvantages ? and is the precession frequency the same ?


John Smith

[Eric Foster]

Hi John,


The frequency is exactly the same as it is still hydrogen nuclei that are giving the signal. Kerosene certainly polarises faster but the precession signal decays faster in the same proportion. This means that the signal measurement has to be done in a shorter time, which can affect accuracy. One advantage of kerosene in cold climates is that is doesn't freeze and burst your bottle.


Eric.

[John Smith]

>Hi John,


>The frequency is exactly the same as it is still hydrogen nuclei that are giving the signal. Kerosene certainly polarises faster but the precession signal decays faster in the same proportion. This means that the signal measurement has to be done in a shorter time, which can affect accuracy. One advantage of kerosene in cold climates is that is doesn't freeze and burst your bottle.


>Eric.


Thanks Eric,


I will experiment with both, I dont have to worry about the freezing water, as I will be using it here in Agulhas ( southernmost tip of Africa where the Atlantic and Indian Oceans meet ) where the sea temperature in winter is over 10 deg C, and up to 28 C in summer )


John