Hanna Instruments EC 214 - Manual (Page 7)

13 12
• Select the appropriate range:
"199.9 μS" for HI 7033
"1999μS" for HI 7031
"19.99 mS" for HI 7030
"199.9 mS" for HI 7034
Note: If the display shows "1", there is an over-range condition.
Select the next higher range.
• Allow a few minutes for the reading to stabilize, then adjust the
“CALIBRATION” knob to read the calibration solution conductivity
value at 25°C (77°F), e.g. 12.88 mS/cm.
• All subsequent measurements will be referenced to 25°C (77°F).
• To reference the measurements to 20°C (68°F), adjust the
“CALIBRATION” knob to read the calibration solution conductivity
value at 20°C (68°F), e.g. 11.67 mS/cm. See the “Conductivity
vs. Temperature Chart” on page 13.
• Calibration is now complete and the instrument is ready for use.
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 %/°C.
Since a small difference in temperature causes a large change in
conductivity, the readings are usually normalized at 25°C.
°C °F HI 7030 HI 7031 HI 7033 HI 7034 HI 7035 HI 7039
(μS/cm) (μS/cm) (μS/cm) (μS/cm) (μS/cm) (μS/cm)
0 32 7150 7 7 6 64 48300 65400 2760
5 41 8220 8 9 6 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
EC 214 manually compensates for temperature differences with a
fixed coefficient of 2%/°C.
EC 215 automatically compensates for temperature differences, and
features an user-selectable coefficient that can be manually adjusted
through a front knob, from 0 (no compensation) to 2.5%/°C.