A year or so ago when I was in the market for my first truly high-quality DMM, I considered getting a Fluke 289 or 287. I really liked the idea of the multiline display, data logging, and onboard trend graphing. I wished it was smaller and had more than 100-hour battery life, but it looked like a great meter.
Then I began reading all the forums about the supercap problems and the tendency of many 287/289 meters to drain their batteries quickly, even when off.
Yikes. After a lot of reading, it
appeared that many of those problems might have gone away with the change Fluke made to a battery backup for the onboard clock, rather than the previous leak-prone supercap. But I decided to play it safe and bought a Fluke 87V instead. I’m glad I did… I really iike the 87-5.
Still… the 289 features looked
pretty cool. My interest in it kept simmering. So I finally pulled the trigger, and it arrived a few days ago. I decided to buy new, so that I wouldn’t have to worry about the supercap issues.
I have a 30 day period to return it if I need to. I really like it and plan to keep it assuming no serious underlying problems crop up. I
suspect, but am
not certain, that all the annoying battery-drain problems that were reported in years past were a side-effect of the supercap issues. Is that correct?
I’ve tested the power consumption on the 289 that I received and have found the following:
- draws about 45mA when powering up
- draws 20-24 mA after power-up with backlight off. Averages 22mA
- draws about 36mA when low backlight is on
- draws 55-60 mA when high backlight is on
- draws about 50 uA when powered off
Now according to my calculations, the measurements above should result in about 100-120 hours of normal usage (assuming 2000-2500 mah alkaline batteries, backlight mostly off)… perhaps even a bit better depending on how the batteries hold out as charge drops below 9V. At a 50 microAmp power drain when switched off, a fresh set of batteries should last for years if the meter sits idle. This all seems to line up pretty well with what Fluke claims for the meter’s power usage.
I’d like to find out about any problems during the 30-day grace period. So far I’m quite happy.
Any reason I shouldn’t be?
No major worries power-wise? Anyone with new recent vintage 287/289s experiencing severe/unexpected battery drain? Any likelihood of problems if/when that little button-battery eventually goes dead? (other than the clock needing reset at main battery change?). Anything else to watch out for?
[BTW, whatever happens, I'll be
keeping the 87V]