6.2
Calculating the ATC Coefficient of a Solution
1.
Set the ATC Coefficient to zero using the procedure detailed in
section 6.1.
2.
Ensure that the temperature function has been calibrated (see
section 5.1). The conductivity function does not need to be calibrated
at this point.
3.
Warm or cool the solution to approximately 5
O
C below the
temperature at which you expect to take sample measurements.
Record the Conductivity and Temperature readings once both have
become stable.
4.
Warm the solution to approximately 5
O
C above the temperature at
which you expect to take sample measurements. Record the
Conductivity and Temperature readings once both have become
stable.
5.
Apply the following formula, where C1 and T1 are the first readings
taken, and C2 and T2 are the second readings taken…
6.
Enter the result that is obtained as the ATC Coefficient of the solution,
as per the procedure detailed in section 6.1.
Note
To assist in calculating the ATC Slope, the following information can be
entered into a spreadsheet. This example has been specifically written for
Microsoft™ Excel™, although the syntax should be similar for other
spreadsheet software.
A
B
1
Conductivity 1
<Enter first Conductivity reading>
2
Temperature 1
<Enter first Temperature reading>
3
Conductivity 2
<Enter second Conductivity reading>
4
Temperature 2
<Enter second Temperature reading>
5
ATC Slope
=100*((10^((LOG10(B3/B1))/(B4-B2)))-1)
A ready-made file can be downloaded from the Downloads section of the
TPS Web Site :
http://www.tps.com.au/downloads
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