Hanna Instruments HI 8734, Instruction Manual

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13 12
The TDS value in aqueous solutions is directly proportional to conduc-
tivity. The ratio between the two parameters depends on the solution
and usually it is set to a factor of 0.5 (corresponding to a solution of
CaCO
3
). This means that 1 µS/cm is equal to 0.5 mg/L (ppm) of TDS.
For manual temperature compensation, refer to the following chart:
TDS VERSUS
TEMPERATURE CHART
For instance, the TDS values of the calibration solutions at 25°C are
1382 mg/L or 12.41 g/L when using
HI 7032 or HI 7036 ,
respectively.
At 20°C, the values are 1251 mg/L or 11.24 g/L, respectively.
With the solutions at 30°C, the values are 1515 mg/L or 13.61 g/L,
respectively.
°C °F HI 7032 HI 7036
mg/L g/L
(ppm) (ppt)
0 32 758 6.82
5 41 876 7.88
10 50 999 8.99
15 59 1122 10.10
16 60.8 1148 10.33
17 62.6 1173 10.56
18 64.4 1200 10.78
19 66.2 1224 11.01
20 68 1251 11.24
21 69.8 1277 11.47
22 71.6 1303 11.71
23 73.4 1329 11.94
24 75.2 1358 12.18
2 5 7 7 1382 12.41
26 78.8 1408 12.65
27 80.6 1438 12.89
28 82.4 1461 13.13
29 84.2 1476 13.37
30 86 1515 13.61
31 87.8 1541 13.85
CONDUCTIVITY VERSUS
TEMPERATURE CHART
The conductivity of an aqueous solution is the measure of its ability to
carry an electrical current by means of ionic motion.
The conductivity invariably increases with increasing temperature.
It is affected by the type and number of ions in the solution and by
the viscosity of the solution itself. Both parameters are temperature
dependent. The dependency of conductivity on temperature is ex-
pressed as a relative change per degree Celsius at a particular
temperature, commonly as percent per °C.
For manual temperature compensation, refer to the following chart:
°C °F HI 7030 HI 7031 HI 7033 HI 7034 HI 7035 HI 7039
HI 8030 HI 8031 HI 8033 HI 8034 HI 8035 HI 8039
(µS/cm) (µS/cm) (µS/cm) (µS/cm) (µS/cm) (µS/cm)
0 32 7150 776 64 48300 65400 2760
5 41 8220 896 65 53500 74100 3180
10 50 9330 1020 67 59600 83200 3615
15 59 10480 1147 68 65400 92500 4063
16 60.8 10720 1173 70 67200 94400 4155
17 62.6 10950 1199 71 68500 96300 4245
18 64.4 11190 1225 73 69800 98200 4337
19 66.2 11430 1251 74 71300 100200 4429
20 68 11670 1278 76 72400 102100 4523
21 69.8 11910 1305 78 74000 104000 4617
22 71.6 12150 1332 79 75200 105900 4711
23 73.4 12390 1359 81 76500 107900 4805
24 75.2 12640 1386 82 78300 109800 4902
25 77 12880 1413 84 80000 111800 5000
26 78.8 13130 1440 86 81300 113800 5096
27 80.6 13370 1467 87 83000 115700 5190
28 82.4 13620 1494 89 84900 117700 5286
29 84.2 13870 1521 90 86300 119700 5383
30 86 14120 1548 92 88200 121800 5479
31 87.8 14370 1575 94 90000 123900 5575
For instance, the conductivity values of the calibration solutions at
25°C are 12880 µS/cm, 1413 µS/cm or 5000 µS/cm when using
HI 7030 , HI 7031 or HI 7039 , respectively.
At 20°C, the values are 11670 µS/cm, 1278 µS/cm or
4523 µS/cm, respectively.
With the solutions at 30°C, the values are 14120 µS/cm, 1548 µS/
cm or 5479 µS/cm, respectively.