Titration - BRAND HandyStep touch Operating Manual

In Titration operating mode, you dispense liquid (standard solution) into another liquid (sample), e.g.
to observe the 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 button. Liquid is dispensed
while you hold down the STEP button. Liquid dispensing stops when you let go of the STEP button or
when the existing volume in the tip is dispensed. Every time the STEP button is released, the dispens-
ing speed is reduced on level (level 8, level 7, level 6 ... level 1). This makes it easier to achieve a color
change point, for example.
'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.
Saving volumes
This function is used to save the most recently set volumes in a list. If you use the same volume set-
tings for the same titration tasks, you can use this function to achieve a color change point more
quickly. To call up a list, see Options, p. 94.

14.2 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
HandyStep® touch, HandyStep® touch S 997486
Prerequisite:
>
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 above the
Erlenmeyer flask.
c.
Hold the STEP button to continuously dispense liquid.
d.
Observe the immersion of the standard solution in the
sample. As you near the color change point, switch to
the mode.
ð
The color change point is distinguished by the first color
streaks in the sample.
e.
Tap on the button. Set the desired volume.
f.
Dispense the solution drop by drop by briefly pressing
the STEP button until the color change is achieved.
14 Titration
or button.
Operating manual
93