2
d. Connect the spout and two 2-way valves to the plastic reagent reservoir.
Note:
There are two 2-way valves below the reagent reservoir. In this
setup, use the bottom valve as an on-off valve (either completely open or
completely shut). Use the top valve as an adjustment valve to adjust to a
slow, consistent rate.
e. Using the utility clamp, secure the reagent reservoir to the stir station
rod. The spout should be aligned just above the three-sided rectangular
opening.
2. Make sure that both 2-way valves are in the closed position (horizontal).
Add about 20 mL of titrant to the plastic reagent reservoir. For this example,
we will use 0.1 M NaOH solution.
3. Before collecting data or calibrating the drops, adjust the flow rate of the
two valves of the reagent reservoir. Temporarily, place another beaker below
the spout of the reagent reservoir. First, completely open the bottom 2-way
valve; then slowly open the top valve until a very slow drop rate is
achieved—a rate of one drop every two seconds, or slower. Close the bottom
valve.
4. Add the solution to be titrated to the 100 mL beaker. For this example, use
about 5 mL of 0.1 M HCl solution. Add enough distilled water so the
solution level covers the bulb of the pH Sensor (about 35 to 40 mL). If you
are going to use a small magnetic stirring bar, less distilled water will be
required (about 1 to 20 mL). Turn on the magnetic stirrer.
Important:
Minimizing volumes of solution titrated and maximizing stirring efficiency
will significantly improve your titration results.
5. Connect the sensor following the steps in the Getting Started section of this
user manual.
Note:
The Drop Counter will only collect data if another sensor
is connected.
6. No data will be collected until the first drop falls through the rectangular
opening of the Drop Counter. Carefully center the spout of the reagent
reservoir to allow the drops to pass through the Drop Counter. Completely
open the lower 2-way valve (the upper valve should still be set to a slow
drop rate). You will now see pH vs. volume data being plotted on a graph.
Connecting via USB
Connected and charging
Orange LED next to the battery icon is solid
when the sensor is connected to Graphical Ana-
lysis via USB and the unit is charging. LED next
to Bluetooth icon is off.
Connected, fully charged
Green LED next to the battery icon is solid
when the sensor is connected to Graphical Ana-
lysis via USB and fully charged. LED next to
Bluetooth icon is off.
Charging via USB,
connected via Bluetooth
Orange LED next to the battery icon is solid
when the sensor is charging. Green LED next to
the Bluetooth icon flashes.
Using the Product
1. Assemble the equipment. (Note: The Vernier Stir Station, pH Sensor, 100
mL beaker, and utility clamp are not included with the Vernier Drop
Counter.)
a. Place a 100 mL beaker on the center of the Stir Station.
b. Remove the storage bottle from the sensor (if applicable). Insert the
sensor body through the larger round hole on the Drop Counter.
c. Slip the Microstirrer onto the bottom of the sensor. Slide the Drop
Counter down the ring stand to a level such that the Microstirrer is very
close to the bottom of the beaker. Tighten the turn screw of the Drop
Counter to hold it firmly in place.
