I intend to purchase a 4ch scope (2405A) which would be used to measure vibration from rotating machinery. My question is regarding triggering the data collection. I need to make a decision regarding how I measure the speed of a rotating shaft and also obtain a phase relationship between the measured vibrations.
I would plan to use channels 2,3 & 4 to measure vibration using accelerometers. The decision I have to make is regarding what signal I can use in CH 1 to trigger the data collection. I can provide a once-per-revolution pulse signal using a displacement probe close to a shaft protrusion such as a screw. I assume this would work but the problem is the cost of this setup is high for a 'hobby'. An alternative is to use an inductive switch sensor which apparently produces a TTL signal.
My first question is very specific and is - "could the TTL signal be used to obtain shaft speed and to provide a phase reference between the vibration signals?"
My second question is more general and is - "how easy would it be to obtain a shaft speed measurement and relative phase measurement between the signals in channels 2, 3 & 4 if a suitable trigger signal could be supplied to channel 1?"