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CONDUCTIVITY CALIBRATION
• It is recommended to calibrate the instrument for the conductivity
range at least once a month, or when the probe is changed.
• For better accuracy, choose a solution with a conductivity value
close to the sample to be measured.
If you are measuring in the mS ranges, calibrate the meter using
the HI 7030 (12.88 mS/cm @25°C) or HI 7034 (80 mS/cm
@25°C) conductivity solution.
For the μS ranges, use HI 7031 (1413 μS/cm @25°C) when
calibrating in the range from 0 to 1999 μS/cm, or HI 7033 (84
μS/cm @25°C) for the 0 to 199.9 μS/cm range.
• Rinse the probe thoroughly with distilled water and, if possible,
use plastic beakers to minimize any EMC interferences.
• Pour a small quantity of the desired conductivity solution into a
plastic beaker, and immerse the probe while making sure that
the holes of the sleeve are completely submerged. Tap the probe
lightly on the bottom of the beaker to remove any air bubbles
trapped inside the sleeve.
• Adjust the conductivity TC knob to 2%/°C.
• Select the appropriate measurement range:
199.9 μS if calibrating with HI 7033 solu-
tion, 1999 μS for HI 7031, 19.99 mS for HI
7030, or 199.9 mS for HI 7034.
Note: If the display shows "1", the reading is
over-range. Select the next higher range.
• Allow a few minutes for the reading to stabi-
lize and adjust the calibration knob to read
the calibration solution value @25°C.
• All subsequent measurements will be referenced to 25°C (77°F).
• If you need to reference the measurements to 20°C (68°F), adjust
the calibration knob to read the calibration solution value
@20°C. See conductivity vs. temperature chart.
• Calibration is now complete and the instrument is ready for use.
CALIBRATION
°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 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
CONDUCTIVITY VS. TEMPERATURE CHART
RESISTIVITY CALIBRATION
• The meter is factory calibrated for resistivity range, and usually
needs recalibration only after a resistivity probe replacement. In
this case, follow the below instructions.
• Immerse the probe in a solution of known resistivity value, and
wait for the reading to stabilize.
• Adjust the calibration trimmer on the rear panel until the
resistivity value of the reference solution is displayed.