BRAND HandyStep touch, Operating Manual

Page: 84 / 234

84
Titration
For information on the function of this mode, see
„Overview of modes“
→ 65. For information on setting the volume, speed, and other operating
steps found in all modes, see
„Operation“ → 67.
Titration in detail
4
3
2
1
5
1. Switch between ‘Manual‘ and ‘STEP Volume’ titration mode.
2. Set the STEP volume. This is possible in the ‘STEP Volume’ titration
mode.
3. Volume already titrated.
4. Amount remaining in the tip.
5. Discard remaining amount or aspirate liquid.
In the Titration operating mode, you dispense liquid (standard solution) into
another liquid (sample), e.g. to observe a color change. There are 2 different
titration modes available for this task:
‘Manual’ titration mode
In ‘Manual’ titration mode, you control liquid dispensing using the STEP but-
ton. Liquid is dispensed while you hold down the STEP button. Liquid dispen-
sing stops when you let go of the STEP button or when the existing volume
in the tip is dispensed.
‘STEP Volume’ titration
mode In STEP titration mode, you specify the STEP volume before dispensing
liquid. Each time the STEP button is pressed, the set volume is dispensed.
The dispensing speed is also reduced each time the STEP button is pressed.
Titration
This section explains how to use the titration operating mode using the color
change of a pH value measurement as an example. You can switch the
titration mode using the
or button.

You will need a transparent vessel, e.g. an Erlenmeyer flask, and the
liquids required for the pH measurement.
a. Select the mode, in order to first dispense a large amount of
liquid. Select the dispensing speed using the button.
b. Aspirate the liquid. Hold the device vertically over the Erlenmeyer flask.
c. Press and hold the STEP button.
d. Observe the immersion of the standard solution into the sample. As you
near the color change point, switch to the mode. The color change
point is identified by the first color streaks in the sample.
e. Tap on the button. Set a small volume.
f. Dispense the standard solution drop by drop until the color change is
achieved.