Good DMM with uA for around 250-300 AUD a pipe dream? - Page 1
Forum section: electronics / general

author: ShortCqt
author_rank: Newbie
timestamp: June 28, 2010, 09:16:26 am
content: After killing another low cost DMM, it's time to get something a bit better. I've set the budget around the $250 AUD mark, prepared to go up to 300 if it's worth it though. The problem is I can't find anything in that price range from a good brand name that supports ?A readings, which Dave says defines an electronics DMM.While I like meters like the Fluke 175, it only measures down to .01mA. So my question is this, is that (10uA) enough to be considered an electronics DMM?My needs? I'm a serious hobbiest, starting to play with wireless sensors, so measuring power usage is a concern with design. Because it's not generating income, I simply can't finance a $700 meter like the Fluke 87.Any comments would be appreciated.ShortCqt

author: Unknown
author_rank: Unknown
timestamp: June 28, 2010, 09:40:02 am
content: Plenty of bench meters go down to the uA level (random example: Keithley 175A's lowest range is 200uA with 4.5 digits, so 199.99uA full-scale, or Keithley 199: lowest range is 30mA with 5.5 digits, so 30.0000mA full-scale). Haven't checked the specs for the accuracy, but I would expect it to be accurate to at least 1uA. These are sometimes available used for under $100 US, but something like the Fluke 87 used will also cost much less than $700 (AUS?). Of course bench meters often lack features like continuity, capacitance and even diode test, so they might not be great as only DMM. And buying used does carry some risk and means you don't have warranty. Bench meters often have less overload protection, since they don't tend to be used in industrial environments; few of them have HRC fuses.You can probably get 4.5 digit meters with a 1uA resolution from lesser brands like Extech or Amprobe for under $250 AUS new. Keep in mind that 1uA precision (i.e. it shows enough digits to resolve 1uA) doesn't mean it's actually accurate down to 1uA. For example, the Fluke 87-V has an accuracy specification of 0.2% + 4 digits for the 600.0 uA range. So for a 1.0uA reading, the tolerance is +/- 0.4uA, i.e. between 0.6uA and 1.4uA. Cheaper meters are likely to be worse.

author: flano
author_rank: Contributor
timestamp: June 28, 2010, 09:46:03 am
content: ShortCqt,I'm in the same boat, I've been looking at the Amprobe AM-160, which you can get shipped from the states for under $300 US, but with the current exchange rate it starts to get expensive quick.I looked into shipping an 87v from the states but Fluke won't let Tequipment export their meters.The other option is eBay, most of the 87v meters go for about $220-240 US + shipping.Hope this helps. Regards Michael

author: saturation
author_rank: Super Contributor
timestamp: June 28, 2010, 10:31:35 am
content: Try Amazon.com; they ship to Oz and the 87V is $300.

author: allanw
author_rank: Frequent Contributor
timestamp: June 28, 2010, 11:03:46 am
content: Could get/make a uCurrent.

author: EEVblog
author_rank: Unknown
timestamp: June 28, 2010, 01:26:13 pm
content: All of the meters in my upcoming $100 shootout are pretty decent, and all have uA ranges.10uA resolution isn't really enough these days, as the sleep current in a micro can be less than that for example.Like others said, buying from the US via ebay/amazon/etc is a very good option, meters are just stupidly expensive from Australian dealers.2nd hand Fluke 87's on Ebay can be great value if you are careful and comfortable with that.The low Aussie dollar hurts at the moment now though :-(Dave.

author: MrPlacid
author_rank: Frequent Contributor
timestamp: June 28, 2010, 01:53:41 pm
content: Quote from: EEVblog on June 28, 2010, 01:26:13 pmLike Dave said. Buy them from ebay. It's much cheaper and get a lot more extras. Here is a tip I use when buying Fluke 87V from ebay. Buy one that look spanking new even if it is used. If it comes with a carry bag. Check closely in the photo if it is also new. I did that and both my ebay flukes came in good, working conditions. I got one as low as $160 USD.

author: ShortCqt
author_rank: Newbie
timestamp: June 28, 2010, 09:50:50 pm
content: Quote from: EEVblog on June 28, 2010, 01:26:13 pmAny idea on ETA Dave? I've got nothing at the moment, while my daughter has a half built beam robotbot waiting for the new DMM, so can put it off for a couple of weeks, certainly not months though.Ta, ShortCqt

author: EEVblog
author_rank: Unknown
timestamp: June 28, 2010, 09:55:18 pm
content: Quote from: ShortCqt on June 28, 2010, 09:50:50 pmSorry, no idea.It's the next major blog on the list I think, but it's a biggie so takes time.Dave.