开云体育

So I'm finally getting to unpack all my gear and set up a lab again. As part of setting up my bench I am doing basic functionality checks on the instruments I intend to use. One is a "straightforward" HP 5335A counter. Hooked it up to a HP signal generator putting out a nice 5 volt sine wave at 1000 Hz. What does the counter tell me? Around 1800 Hz and unsteady. Analog scope tells me it looks great, nice and clean... Try it again on the counter and 1000 Hz on the nose and rock solid. I've found in the past that it is very easy to get the second harmonic reading on a counter as well. And DVMs, forget about it, some read AC riding on DC very strangely, or if you have a non-true-RMS meter...

There are many cases where you need to understand what you are looking at and what you are expecting. You need this to sanity-check the instrument as well as to understand what you need to do to verify your reading. Yes, analog scopes can show you a very true picture of what's happening but you can easily miss some massive fast/short transients too.

To get the most from this gear you need to understand each instrument and what it's limitations are. You need to know your tools.

Now what's up with that 5335A and the strange result I am now unable to duplicate? ;-)

Now back to work...