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PH220-en-US_v3.5 3/21
Measuring pH
NOTE: Electrodes should always be rinsed before and between samples
with distilled or DI (de-ionized) water to remove all traces of storage
solution, process media, or previous test solution.
1.
Connect the pH electrode to the meter.
2.
Turn the meter ON using the ON/OFF button
. Wait for the self-test (‘SLF tSt’) to finish.
3.
Use the MODE button to select pH mode. The unit of measure appears on the LCD.
4.
To change the unit of measure for temperature, press and hold the MODE button for 2
seconds. The LCD reflects the current unit of measure.
5.
Rinse the electrode with distilled or deionized water.
6.
Place the electrode in the solution. Allow 30 seconds for the electrode/ATC to reach
thermal equilibrium with the buffer solution.
7.
After the measurement stabilizes, view the pH reading on the main display. An out of range
reading is indicated by the display icon ‘HHH’. Note that ‘HHH’ will also display when the
electrode is disconnected.
8.
When the test is complete rinse the electrode with distilled or deionized water.
Automatic Temperature Compensation (ATC)
The millivolt output of a pH electrode varies with temperature, and so the meter must
compensate for these variations. The PH220 automatically compensates for solution
temperature changes with the electrode’s built-in thermometer. The temperature compensation
is active when the solution temperature deviates from room temperature. The temperature of a
solution is displayed on the lower LCD line.
Automatic Power OFF
To conserve battery power, the instrument automatically shuts off after 10 minutes of inactivity.
To disable or enable this feature, follow the steps below:
To disable: With the power on, press and hold the on/off button
for 2 seconds (‘oFF’
and ‘AtP’ will display). The Auto Power OFF feature is now disabled.
To enable: With the power on, press and hold the on/off button for 2 seconds (‘on’ and
‘AtP’ will display). The Auto Power OFF feature is now enabled.
Each time the meter is turned off the Auto power OFF feature is set to the enabled mode.
