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mEASurEmENT
12. MEASUREMENT
Options: Direct Readings, Direct/Autohold Readings
When Direct is selected, sample measurements are displayed continuously.
When Direct/Autohold is selected, measurement reading is held on display when measurement
stability is reached. This option removes the subjective nature of stability as a measurement that has
not reached equilibrium will not be used. Only after the chosen stability criteria has been met will the
meter go into the Direct/Autohold mode.
12.1. MEASUREMENT TIPS
1. Connect the electrode to be used to the appropriate meter input. Make sure the electrode has
been recently calibrated and is working correctly.
2. Place electrode into the HI764060 electrode holder for easy transfer in and out of containers
during calibration, sample measurement, and storage.
3. Rinse with purified water between buffers and / or samples.
4. Blot (never rub) the glass pH sensor with a lint-free tissue between buffers and samples.
5. To limit sample contamination, pour 2 beakers of buffers and samples. Use one beaker to rinse
the sensor, and then use the second for measurement.
6. Gently stirr the test sample to ensure the sensor is measuring a representative sample.
7. Open the fill hole cover and keep the fill solution topped off to permit the fill solution to flow
through the ceramic junction and maintain a stable reference signal.
Note: Use the same size beaker and immersion depth for samples and buffers.
8. If measuring across a temperature gradient, allow the sensor to reach temperature equilibrium.
If using manual temperature compensation input the sample temperature.
9. Once the reading indicates Stable, record measurement data.
10. Remove the electrodes from the sample, repeat steps 3, 4 and then place into the next rinse,
then test sample.
11. Repeat the procedure for all samples. When all samples have been measured, rinse the pH
electrode and replace storage cap with storage solution. Replace fill hole cover.
Note: When working without a temperature sensor, ensure that both calibration and
measurements are done at the same temperature. This requires manual input of temperature
value to allow the meter to perform buffer temperature correction.
12.2. DIRECT READINGS
From Measurement screen, tap the Measurement Menu icon ( ) on display. Next,
• Tap to select from supported parameters.
• Tap Direct to select direct Reading Mode.
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