Right. The other thing is that you need 4 ~ 5X the horizontal speed of our signal on a digital scope to have basic signal fidelity. You can have RF and show a trace that looks flat and clean. An analogue scope will show a band across the screen if the horizontal setting is far off the signal (high or low).
Another issue is that you have no real low level detail with a DSO, so my old Philips PM3070 will show much better low level detail than my Keysight MSOX3104T in 12 bit mode. Settings in the DSO can have a huge effect on what you see on the screen.
Features. The FFT function on scopes I have seen are not useful compared to a spectrum analyzer. So scratch that idea. They can measure voltage, but not terribly accurately. Same for frequency. The average oscilloscope we can afford gives an approximate idea of voltage and frequency. Calibrated lab scopes are much better but we cannot afford to keep those in calibration much less to buy them.
Take it from someone who has bought many scopes through their career, and I currently have some ghastly expensive scopes. For service and even some research, you really do what a half decent analogue oscilloscope. Cheap instruments will never be accurate, and if they do have some initial accuracy, they will not hold it. That is the reality of electronics. Really good equipment does hold it's calibration pretty well.
Another issue is that you have no real low level detail with a DSO, so my old Philips PM3070 will show much better low level detail than my Keysight MSOX3104T in 12 bit mode. Settings in the DSO can have a huge effect on what you see on the screen.
Features. The FFT function on scopes I have seen are not useful compared to a spectrum analyzer. So scratch that idea. They can measure voltage, but not terribly accurately. Same for frequency. The average oscilloscope we can afford gives an approximate idea of voltage and frequency. Calibrated lab scopes are much better but we cannot afford to keep those in calibration much less to buy them.
Take it from someone who has bought many scopes through their career, and I currently have some ghastly expensive scopes. For service and even some research, you really do what a half decent analogue oscilloscope. Cheap instruments will never be accurate, and if they do have some initial accuracy, they will not hold it. That is the reality of electronics. Really good equipment does hold it's calibration pretty well.
Calibration is checking to make sure they are within tolerance. Calibration and adjustment is correcting a problem, or perhaps service to fix something. I have some Tek lab scopes here. But the process to certify an instrument is not cheap. I used to do that job.
Modern lab scopes, spec-ans, sig-gens are mostly self-calibrating, but the software/firmware needs to be fully tested, and any internal references need to be checked and adjusted. Still costs a boatload of money. Even though they typically aren’t turning a bunch of pots it’s still time consuming. Ask anyone who is waiting on a bench that is down for cal. Why they always schedule lab calibration to coincide with end-of-quatrer commitments is beyond understanding.
lol!
Our customers learned and staggered their calibrations.
Yes, closed case cal or open case ran through the same stimulus and reading steps. The main difference was closed case units could sometimes be controlled by software programs and you basically pressed go, and moved leads occasionally. Everything else was automatic, including recording the readings ome times with 'scopes. Meters normally sent the readings on the bus. Software control saved a huge amount of time unless the instrument failed or was OOT.
Our customers learned and staggered their calibrations.
Yes, closed case cal or open case ran through the same stimulus and reading steps. The main difference was closed case units could sometimes be controlled by software programs and you basically pressed go, and moved leads occasionally. Everything else was automatic, including recording the readings ome times with 'scopes. Meters normally sent the readings on the bus. Software control saved a huge amount of time unless the instrument failed or was OOT.