Re: Thermal Conductivity Sensors

[John Manwaring]

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> I am going to be calibrating some of the Campbell Scientific 229 sensors.
>  I am going to use pressure from 0-400 kPa but I would like to calibrate
> at a higher kPa.  I read somewhere that letting the sensors "hang" in a
> jar containing a solution of potassium sulfate at 20 degrees Celcius will
> give an equivalent total suction of 4120 kPa.  Do you know of a solution
> (and temperature) that might give an equivalent total suction between 400
> and 4120 kPa?  I would really appreciate the input.

m (molality)        15C          20C      25C      30C      35C
   0.1 m       -0.447 MPa   -0.454   -0.462   -0.470   -0.477
   0.2 m       -0.884 MPa   -0.900   -0.915   -0.930   -0.946
   0.5 m        -2.22 MPa    -2.241   -2.281   -2.322   -2.362
   1.0 m       -4.459 MPa   -4.550   -4.640   -4.729   -4.815

This is for NaCl and is taken from Lang (1967).  I have more 
extensive tables for both NaCl and KCl, if you need them.

		--John Manwaring