Hanna Instruments HI 2550 User Manual

Page 8

3 cm

(1¼")

• The pH is displayed on the primary LCD and the temperature on the

secondary LCD.

• If the 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 recommended
to rinse the electrode thoroughly with deionized water or tap water 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, the temperature effect must be compensated for. To use the
Automatic Temperature Compensation feature, connect and submerse
the HI 7662 temperature probe into the sample as close as possible to
the electrode and wait for a few seconds.
If the temperature of the sample is known, manual temperature
compensation can be used by disconnecting the temperature probe.
The display will show the last temperature reading with
the “ºC” tag blinking.
The temperature can now be adjusted with the ARROW
keys (from –20.0 ºC to 120.0 ºC).

mV/ORP MEASUREMENTS

mV/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.
• Press RANGE to enter mV range.
• Submerse the tip of the ORP electrode (3 cm/1¼”)

into the sample to be tested and allow a few
seconds for the reading to stabilize.