I am using a Pico ADC-212 oscilloscope to try to verify the existence of voltage "spikes" in our data collection system. We have a Keithley 2701 collecting data at regular intervals that will periodically report high voltages. I hooked up the oscilloscope to one of the channels the 2701 is measuring to see if the voltage really is what is being reported. I set up the scope for a one shot measurement and set the trigger to ~8V. The trigger was activated at the same time the collection system recorded a spike. However, the output from the scope showed that the voltage was never anywhere near 8V. How could the scope trigger when the does not cross the trigger level? I have screen shots that show the voltage trend after the trigger event, but I don't know how to attach them.