9
R
A
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G
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probe approximately 3 cm (1¼”) into the sample to be tested and stir
gently. Allow time for the electrode to stabilize.
• The pH is displayed on the primary LCD and the temperature on the
secondary LCD.
• The pH reading is out of range, the closest full‑scale value will be
displayed blinking on the primary LCD.
If measurements are taken successively in different samples, it is recom‑
mended to rinse the electrode thoroughly with deionized water or tap wa‑
ter and then with some of the next sample to prevent cross‑contamination.
The pH reading is affected by temperature. In order to measure the pH
accurately, this temperature effect must be compensated for. To use the
Automatic Temperature Compensation feature, connect and submerse
the
HI7662
temperature probe into the sample as close
to the electrode as possible and wait for a few minutes.
If the temperature of the sample is known, manual
compensation can be performed by disconnecting the
temperature probe.
The display will show the last recorded temperature
reading with the “
°C
” symbol blinking.
The temperature can now be adjusted with the
ARROW
keys (from
‑20.0 ºC to 120.0 ºC).
ORP MEASUREMENTS
An optional ORP electrode must be used to perform ORP measurements
(see Accessories).
Oxidation‑Reduction Potential (REDOX) measurements provide the
quantification of the oxidizing or reducing power of the tested sample.
The surface of the ORP electrode must be clean and smooth in order to
obtain an accurate measurement.