EEVblog Electronics Community Forum
General => General Technical Chat => Topic started by: skysurf76 on July 16, 2011, 08:19:52 am
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I am an electrical engineering student, and I tinker around with microcontrollers and I have a few projects going on, and after watching Dave's videos I have the compulsion to buy equipment. On craigslist in my area I found a fluke scopemeter 99b series 2 for sale. The guy wanted 300 but I offered 225 and he accepted and gave me his cell phone number. I was wanting to go out on Sunday and see it and most likely buy it, then I became terrified when I realized I have no idea really about what I'm buying and realized I need some knowledgeable advice.
I currently only have a 30 dollar sears el' cheapo multimeter and I had my eye on a fluke 87 V because I want a "real" multimeter, and I figured with a fluke scopemeter, even if it is old, I would be getting a reliable fluke multimeter at least as good as an 87V with logging capabilities with an oscope to boot.
Buy, don't buy, what questions to ask when I get to the guys house, what to check on the meter, bad price, good price?
Thanks so much in advance to anyone taking the time to answer. :)
P.S. He said it was calibrated in March. Should I ask for documentation?
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Calibration is worthless without documentation!
If you calibrate a scope or a multimeter you only make a normative-actual value comparison on the calibraion document. A calibration doesn't change anything on your device!
calibration =|= alignment
You should check all buttons and the display. Maybe there are some dead pixels or dead columns/row
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The 99b has a real time sampling rate of 25MS/s, so its usable frequency is 2.5 MHz, single shot.
Its basic DC accuracy is 0.5% and 2-3% in AC to about 20kHz; the 87V is 0.05% and 1% respectively.
It cannot measure amps without the optional probe, and even then its limited to the probe's capacity.
It is not CAT rated.
For $200 I'd buy a used 87V as it will last you a lifetime and its a modern instrument. 2.5MHz is fairly limited even if fairly low cost.
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A scopemeter is far more versatile than a DMM.
If you get the accessories like the probes and power supply I go for the scopemeter.
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The 99b has a real time sampling rate of 25MS/s, so its usable frequency is 2.5 MHz, single shot.
Its basic DC accuracy is 0.5% and 2-3% in AC to about 20kHz; the 87V is 0.05% and 1% respectively.
It cannot measure amps without the optional probe, and even then its limited to the probe's capacity.
It is not CAT rated.
For $200 I'd buy a used 87V as it will last you a lifetime and its a modern instrument. 2.5MHz is fairly limited even if fairly low cost.
Thanks a lot Saturation, that did it for me. I decided to pass on the scopemeter. After reading your post I did some more research and sure enough they just about had me with the 5 gigasample per second claim. Thanks for pointing out the true bandwidth. Additionally I had no idea the accuracy of the 87V was so much better. I think I'll just keep looking for an 87V.
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Good luck!
On eBay, buy it now 87V typically about $230, if you bid the lows are in the $160 and high in the $250.
http://cgi.ebay.com/FLUKE-87V-TRUE-RMS-MULTIMETER-/220814619419?pt=LH_DefaultDomain_0&hash=item336993b31b (http://cgi.ebay.com/FLUKE-87V-TRUE-RMS-MULTIMETER-/220814619419?pt=LH_DefaultDomain_0&hash=item336993b31b)