Carl Roth COND 50 VioLab, Instruction Manual

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18
UM Serie 50VioLab EN rev.1 19.05.2020
EN

Calibration with manual values
Example : two-point calibration pH 6.79 e pH 4.65 (DIN19267)

Access the Setup menu for pH and select in P1.1

Custom, press twice the key to return to the
measurement and position in pH mode .

Press to enter the calibration mode.

Rinse the electrode with distilled water and gently dab with paper towel. Dip the electrode in the first
pH buffer solution (e.g. pH 6.79).

Wait for the pH value on the display to stabilize; when the icon appears and the value flashes,
modify it using the directional keys by entering the correct one (e.g. pH 6.79), as suggested by the
string “ADJUST THE VALUE” and by the icon .
Note: Check the buffer value according to the temperature

When the icon appears again, press the key to confirm the first point; the actual measured
value flashes on the display and the beaker icon appears with the buffer identification colour .
..

Remove the electrode, rinse with distilled water, dab gently with paper towel and dip it in the next
buffer (e.g. pH 4.65).

Wait for the pH value on the display to stabilize; when the icon appears and the actual value
flashes, modify it using the directional keys by entering the correct one (e.g. pH 4.65), as suggested by
the string “ADJUST THE VALUE” and by the icon .

When the icon appears again, press the key to confirm the second point; the actual
measured value flashes on the display, the Slope% and, next to the first beaker, the icon with identifying
colour of the second buffer appears.

At the end of the second calibration point, the instrument automatically returns to measure mode.

To perform a one-point calibration just press the key after finishing the first point.
Note: If you are working with manual temperature compensation (MTC), update the value before calibrating
the instrument.

Performing pH measurement

In measure mode, press the key and move to the pH parameter indicated by the icon .

Connect the electrode to the pH / ORP BNC of the instrument (green).

If the user does not use an electrode with a built-in temperature probe or an external probe NTC 30KΩ,
it is recommended to manually update the temperature value (MTC).

Remove the electrode from its tube, rinse with distilled water and dab gently with paper towel.

Check the presence and eliminate any air bubbles in the membrane bulb by stirring vertically (as for
the clinical thermometer). If present, open the side cap.

Dip the electrode in the sample, while keeping it slightly stirred.

The scrolling on the display of four red bands means that the measurement is not stable yet.

Consider the measurement truthful only when the stability icon appears .