I'm wanting to count the number of drops coming out of a burette. Am I able to set up a photogate to do this or do I have to but the drop counter. If not, am I able to set up a keyboard input in logger pro to maunually count the number of drops and graph it aginst the pH.
Thanks
It is pretty easy to count events (including drops) that interrupt the photogate beam. In what follows, I'm assuming that you are using Logger Pro with one of Vernier's interfaces. A similar technique can be used with those interfaces that also work in a stand alone mode (LabQuest and LabQuest 2).
Connect the photogate to your interface and the interface to your computer.
Start Logger Pro
Go to the Experiment>>Set Up Sensors menu and select your interface.
When the window opens showing your interface, click on the image of the photogate on the sensor port. A drop down menu will appear. Select Photogate Timing. Close the window.
Now you will need to add a calculated column to get the total number of events. The photogate will log a "1" every time the gate is blocked. The calculated column you create will use the formula sum(GateState). This will give you the total number of events seen by the photogate.
If you like you can insert a graph showing this total.
If you use this approach, you will still need to determine the volume of a drop to multiply by the number of drops seen.