DSPH-1/TDS-4 - Setting up the Meter, Calibrating Meter

Setting Up the Meter

Installing the Battery (Fig 2) Carefully remove the meter from the carrying case making sure you donÆt lose the small screwdriver and detergent in a small plastic bag.

To install/change the battery, do the following:
1. Insert your thumb in the recessed area of the battery compartment door and pull it away from the display.

2. Snap the 9V alkaline battery into the battery clip.

3. Place the battery clip/battery assembly at the top of the battery compartment.

4. Replace the battery compartment door and snap into place.

Figure 2. Installing the Battery

Setting Up the Electrodes
When you are ready to take your measurement(s), you must first remove the protective covers (caps) that are in place for storage. The pH electrode has the soaker bottle in place to protect the glass bulb inside the plastic sleeve, to protect from contamination and to prevent the electrode from drying out. The red cover (cap) covers the conductivity electrode, preventing fluid from entering the electrode when only pH is being measured and reduces the need for cleaning.

Setting Up the pH Electrode (Fig 3)
To remove the soaker bottle,
1. Extend the electrode pair to the 90░ position.
2. Hold part of the electrode shafts and the white cap with one hand.
3. With the thumb and forefinger of the other hand loosen the bottle a couple of turns and slide the bottle and cap off carefully.

To put the bottle back on the electrode shaft, reverse the process stated above.

Setting Up the Conductivity Electrode
To remove the cap, merely pull it off of the electrode shaft.

Figure 3. How to Loosen Bottle

Calibrating the Meter
The meter is factory calibrated prior to shipping. However, since the electrode outputs change with age and condition it is important to calibrate with fresh pH buffers and known conductivity solutions prior to each use. Zero and span adjustments interact during calibration. Repeat calibration sequence at least two times or until readings stabilize. Rinse electrode in a separate distilled or deionized water container before dipping the electrode in pH7 solution to avoid contamination. Cross contamination of calibration standards will cause the appearance of ôdriftö in the instrument.

pH Mode
For best results, calibrate pH with a buffer that is within 3 pH units of the test sample.
1. Rinse the pH electrode in distilled or deionized water.

2. Insert in a fresh pH7 buffer solution.

3. Slide back the battery compartment door to the first stop, exposing the adjustment potentiometers (pots). Refer to Figure 1.

4. Adjust the CAL pot until the display reads 7.00.

5. Remove electrodes, rinse in distilled or deionized water and insert in a pH4 or pH10 buffer solution.

6. Adjust the SLOPE pot until the display reads the correct value.

Conductivity Mode
1. Rinse electrodes thoroughly by agitating in distilled or deionized water.

2. Wipe off conductivity electrode and allow it to dry.

3. When dry, conductivity should read ô0ö in air.

4. Adjust ZERO pot if reading is incorrect. If the conductivity electrode does not zero, it may indicate dried solids on the sensor. Clean with a mild detergent solution (such as Ivory).

5. Immerse electrode in a known conductivity solution. Choose a conductivity calibration solution that is near the range of the samples to be measured. Adjust SPAN pot to desired conductivity value.

6. Rinse electrodes and return to storage compartment.

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