General Tools and Instruments DPH230SD - Manual (Page 9)

2. To measure the pH of a solution, press the ▼ button until the display shows the term
“pH”. Make sure the pH electrode is seated firmly in the BNC socket (callout 1-14 of
Fig. 1) on the top of the meter. If the ATC temperature probe is being used, make sure it
is seated firmly in its socket (callout 1-13 of Fig. 1) on the top of the meter as well. If the
ATC probe is not being used, perform the last step of procedure to manually match the
compensation temperature to the temperature of the solution being tested.
Holding the pH electrode by its handle, immerse it in the solution under test. (If you are
using the ATC temperature probe, immerse its head in the solution as well.) Gently shake
the electrode (and probe, if used) to help any air bubbles escape and to ensure an accurate
reading.
The display will simultaneously show the solution’s pH in the center and either the
manually selected compensation temperature or the actual temperature of the solution
(as measured by the ATC probe) below it. By default, the temperature reading will be in ºC,
unless ºF has been selected.
3. To measure the ORP of a solution, press the ▼ button until the display shows the term
“mV”. Plug an optional ORP electrode with a BNC connector into the same socket on the
top of the meter (callout 1-14 of Fig. 1) that accepts the plug of a pH electrode.
Holding the ORP electrode by its handle, immerse it in the solution under test. Gently shake
the head of the electrode to help any air bubbles escape and to ensure an accurate
reading. The display will show the ORP of the solution, in mV.
Whenever the DPH230SD is in measurement mode, you can turn off the backlight (which is
on by default) by briefly pressing (but not holding) the POWER/ESC button. To reactivate the
backlight, briefly press the button again.
Whenever the instrument is in measurement mode, you also can check the current date
and time by briefly pressing the TIME button. Doing so causes both values to appear briefly
at the lower left of the display.
HOLDING AND STORING MEASUREMENTS
1. To hold a measured value of pH or ORP, press the HOLD/ESC button during the
measurement. Doing so will cause the word “HOLD” to appear at the top of the display.
Pressing the HOLD/ESC button again releases the hold.
2. To record and recall readings, press the REC/ENTER button while making
measurements. This will make the term “REC” appear at the top of the display. Pressing
the REC/ENTER button again, briefly, will make the term “MAX” appear to the right of
“REC” and switch the display to the maximum value stored in memory during the last
recording session. Pressing the REC/ENTER button again, briefly, will make the term
“MIN” appear to the right of “REC” and switch the display to the minimum value stored
during the last session.
3. To exit recording mode, press and hold the REC/ENTER button for at least three
seconds, until the term “REC” disappears from the top line of the display. The display
will then revert to showing the current reading.
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