Soil Thermal Resistivity

[timm333]

I am trying to figure out what are the correct units of soil thermal resistivity. The acceptable soil thermal resistivity is 0.9. In NEC they call it 0.9 C.m/W, but in IEC they call it 0.9 K.m/W. (Where C.m/W = [degree Centigrade.meter/watt], and K.m/W = [degree Kelvin.meter/watt]). I am trying to figure out why the value "0.9" does not change even though the units are change. Thanks for help.

 

[junkhound]

I am trying to figure out what are the correct units of soil thermal resistivity. The acceptable soil thermal resistivity is 0.9. In NEC they call it 0.9 C.m/W, but in IEC they call it 0.9 K.m/W. (Where C.m/W = [degree Centigrade.meter/watt], and K.m/W = [degree Kelvin.meter/watt]). I am trying to figure out why the value "0.9" does not change even though the units are change. Thanks for help.

0 C = starts at freezeing point of water, 0 K starts at absolute zero. Units have same dimension, so 0.9 does not change.

Just like F and R unless that is just more confusing?

 

[timm333]

Ok

 

[Phil Corso]

Timm,

The units are equal because you are dealing with temperature change! That is, deg ⁰C (differential) is equal to K (differential)! Also, the correct units are ⁰C·m/W, and K·m/W! There is no deg ‘⁰’ assigned to K!

Regards, Phil Corso