LaMotte Tracer Salt Meter - Manual (Page 12)

NOTE: When measuring samples with low conductivity, thoroughly
rinse the probe with distilled or deionized water before placing it in the
sample to avoid contamination of the sample with electrolyte from the
pH reference electrode. Also increase the sample size to 200 to 500 mL
to decrease the chance of contamination. If a sample cup is used, do not
allow the probe to sit in the sample for any longer than necessary to
avoid electrolyte leakage into the sample. Leakage will raise the
conductivity level.
Measuring the TDS of Soil
1. Fill a 50 mL beaker with the soil sample. Tap the beaker lightly on a
hard surface to remove trapped air. Remove excess soil from the
surface.
2. Empty the soil into a 250 mL wide-mouth flask.
3. Add 100 mL of distilled water. Stopper and shake vigorously.
4. Wait 30 minute. (Shake the flask vigorously three or four times
during this period.)
5. Filter the contents of the flask. Collect the filtrate in a beaker.
6. Rinse the electrode with distilled or deionized water to remove
impurities.
7. Press the ON/OFF button to turn the TRACER on. Make sure the
meter is in the TDS mode.
8. Immerse the electrode in the filtrate. Make sure the tip of the
electrode is completely immersed.
9. Stir the filtrate with the electrode to create a homogeneous solution.
10. Gently stir the filtrate with the electrode. Read the TDS value of
the filtrate from the display.
11. Rinse the electrode in distilled water. Replace the cap.
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