EEVblog Electronics Community Forum
Electronics => Beginners => Topic started by: Airnautique on June 05, 2019, 05:19:28 pm
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Hey all,
Quick question regarding network analyzers. Is it better to leave them on when not in use, or to turn them off? At my internship they always left their network analyzer powered on. At my current job I've been told it isn't good for it to be left on overnight/over the weekends. So which is it? The network analyzer in question is an Agilent E5071C.
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Well you could argue about this for any other piece of test equipment, or any other kind of electronics.
Turning things on and off does put electronics trough extra stress as it might transition trough some rough events during it and the effect of thermal expansion as it heats up and cools down can put stress on various parts of it. The thermal cycling can also cause references such as crystal oscillators of precision voltage references to drift more than usual. Some equipment also needs a lengthy few minute warmup before it provides the most accurate of measurements. So there are reasons why you might keep a piece of test gear running 24/7
But then again running constantly racks up extra operational hours. This could cause more deterioration in some components such as capacitors, fan bearings etc. Displays also tend to have a lifetime, be it the segments of a VFD display, the phosphor of a CRT screen, the CCFL backlight tube, or the LEDs in a LCD backlight. So plenty of arguments of why you might not want to run something 24/7
Hard to say what is better for this particular network analyzer, but don't worry about it and just do as you are told. If it breaks its going to cost the company to repair anyway. Tho if the reason it broke is because you sent 100W of RF into one of the test ports, then maybe you should worry at least a bit as these thing was surely not cheap.
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I don't think it matters much one way or another. I can't think of anything particularly special in a VNA in this regard, so the issues Berni posted about displays, capacitors, and fans are basically the type of things to worry about, similar to pretty much any other piece of equipment although the bill for a failed power supply or fan is probably going to be a lot higher than your desktop PC, at least if you are getting it serviced by keysight.
Another concern might be a power failure. They usually run windows of some sort, so you might worry about an unclean shutdown. But they should be pretty resilient against that sort of thing as long as you haven't mucked with the software.
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Some equipment also needs a lengthy few minute warmup before it provides the most accurate of measurements.
Big boxes needs more than just few minutes. Some1 who say that his instruments are running 24/7 is just lazy, always in a hurry or both. Manufacturers recommend 30 minute warm-up for hi-end signal analyzers and VNA's. Usually you do not switch them off till end of the day unless you are sure that you will not use them.