An accessory, which can be attached to CMA Photogate 185164 or CMA Photogate 292050
and used to record the volume of titrant added during titration experiments. During such experiments pH and temperature are easy to measure with respective sensors, but volume is not. A drop counter offers a simple way to measure volume. A drop-forming tip delivers drops of constant volume size, which are detected by the photogate. Counting added drops gives the total added volume.
The Drop Counter connects to the photogate via a slider. When properly positioned, a drop of titrant will block the infrared beam of the photogate each time a drop passes through. A LED indicator located on the photogate flashes each time such event happens. The Drop Counter has two round holes, larger hole for a pH electrode and smaller hole for a temperature sensor. It is delivered together with:
a plastic 20-mL syringe with Luer-lock, by removing the piston the syringe becomes a titrant solution reservoir,
two 2-way valves with Luer-lock connectors, and
a plastic tip.
The drop dispenser is assembled by connecting two 2-way valves to the reservoir and attaching a tip to the second valve. One of the valves is used as an on-off valve (either completely open or completely shut) and one as an adjustment valve, to adjust to a slow, consistent rate.