Hach-Lange 3705 sc - Manual (Page 20)

18
Operation
4.7 Calibration
Calibration Methods When Measuring Conductivity:
• Sample Cal Method: Enter the known conductivity value of the sample
determined by laboratory analysis or a comparison reading.
• Conductivity Cal Method: Enter the known conductivity value of calibration
solution, and its linear % per °C and reference temperature values.
• Zero Cal Method: Enter the zero value (in air).
Calibration Methods When Measuring Percent Concentration:
• Process Cal (Conc) Method: Enter the known % concentration value of
calibration solution (ideally, process solution)
• Conductivity Cal Method: Enter the known conductivity value of calibration
solution, and its linear % per °C and reference temperature values.
• Sample Cal Method: Enter the known % concentration value of the sample
determined by laboratory analysis or a comparison reading.
Calibration Methods When Measuring TDS
• Process Cal (ppm) Method: Enter the known TDS ppm value of calibration
solution (ideally, process solution)
• Conductivity Cal Method: Enter the known conductivity value of calibration
solution, and its linear % per °C and reference temperature values.
• Sample Cal Method: Enter the known TDS ppm value of the sample determined
by laboratory analysis or a comparison reading.
4.7.1 Preparing a Conductivity Reference Solution
Add the listed grams of pure, dried NaCl to one liter of high-purity, deionized, CO
2
-free
water that is at a temperature of 25 °C.
Table 6 Conductivity Reference Solutions
Desired Solution Value
Grams NaCl To Be Added
µS/cm mS/cm ppm (NaCl)*
200
500
1000
0.20
0.5
01.00
100
250
500 0.1
0.25
0.50
2000
3000
4000 2.00
3.00
4.00 1010
1530
2060 1.01
1.53
2.06
5000
8000
10,000
5.00
8.00
10.00
2610
4340
5560 2.61
4.34
5.56
20,000
50,000
100,000
20.00
50.00
100.00
11,590
31,950
72,710 11.59
31.95
72.71