Vernier Tech Info Library TIL #2031

Question

Is it possible to use VP-BTA when doing an Ohm\'s Law-type of experiment, or is the differential probe required?

Answer

You can use the standard voltage probe (VP-BTA) to do ohm's law experiments. There are two things you need to watch out for and those are the reasons we recommend the Differential Voltage Probe for these experiments.

- When the red and black leads are not connected to anything, you will get a reading of a few volts. This can confuse students. If you connect the red and black leads together, the voltage probe will read zero. With the Differential Voltage Probe, the reading will be very close to zero, even when nothing is connected.

- Be careful if you use two of the regular voltage probes at the same time. Note that the black wires of each probe are connected to the common ground of the interface and therefore they are connected together. This can cause unexpected results when two are used at once. The Differential Voltage Probe does not share a common ground, so you can easily use 2 of the sensors in the same circuit at the same time, and they will not interfere with each other.

Related TILs:
TIL 1076: What is the difference between a Differential Voltage Probe and the simple LabPro voltage probe?

Created by: dvernier on July 01 2009
Last updated by: jhopkins on July 14 2009