When using a teaching series PowerLab's built-in stimulus isolator and Bio Amp for experiments, do not short circuit the unit's stimulus isolator outputs to its Bio Amp inputs. While doing this will not immediately damage the PowerLab, the input circuit components in the Bio Amp will fail prematurely if this condition is allowed to occur multiple times over extended periods.
If students are using metal dissection pan, care should be taken to NOT push the pins all the way through the tissue and dissection mat, making contact with the metal pan below, and shorting the unit's inputs and outputs. In addition to potentially damaging the unit long-term, the shorting of the stimulus outputs and amplifier inputs will make it impossible to record good data. If pins are consistently being pushed through to the metal pan below during labs, consider using plastic dissection trays instead.