Fluke 15B  - Page 1
Forum section: electronics / testgear

author: Zepnat
author_rank: Regular Contributor
timestamp: March 29, 2014, 11:05:53 pm
content: Hi I've seen the Chinese only market Fluke 15B for a reasonable price but I question the accuracy. As an example the DC range seems rather large variation at +/-1% and 10 counts.Ignore I used 0.1% instead of 1% in my calculationSo if it reads 3.800v the actual value could be between 3.814v or 3.786vAnd what if the input voltage is 12.60v is it possible to read between 12.72v and 12.49v please correct me.I will watch daves multimeter shoot out next week when I can get back onto youtube.Excuse my ignorance I've never got used to these instruments since they went digital.AC Current Range : 0.1UA to 10ADC Current Range : 0.1UA to 10AAC Range Voltages : 0.1Mv to 1,000VDC Range Voltages : 0.1Mv to 1,000VResistance Range : 0.1 ohm to 40MohmCapacitance Range : 0.01nF to 100uFAC Current : 400uA / 4000uA / 40mA / 400mA / 4A / 10AResolution : +/-1.5%+3DC Current : 400uA / 4000uA / 40mA / 400mA / 4A / 10AResolution : +/-1.5%+3AC Voltage : 400mV / 4V / 40V / 400V / 1000VResolution : +/-3.0+3DC Voltage : 400mV / 4V / 40V / 400V / 1000VResolution : +/-1.0+10Resistance : 400 / 4K / 40K / 400K / 4M / 40M OhmResolution : +/-0.5%+3Capacitance : 50nF/ 200Nf / 2Uf / 20Uf / 200Uf / 20MfResolution : +/-2%+5It is at banggood for $58

author: Fsck
author_rank: Super Contributor
timestamp: March 29, 2014, 11:21:37 pm
content: Why do you question the accuracy? The allowable error is large, yes; probably intentional so they don't risk compromising their "rest of the world" lines, and to what they find suitable for the price including their value of brand name.

author: retiredcaps
author_rank: Super Contributor
timestamp: March 29, 2014, 11:25:35 pm
content: The 15B manual states for DCV0 to 400mV is 1.0% +/- 10 counts (in mV range)0 to 1000V range is 0.5% + 3 counts (in V range)For 12.60V, that means12.60 * .005 = 0.063.12.60 - 0.063 = 12.537 or 12.54 rounded up. Now subtract 3 counts. The lower range is 12.51.12.60 + 0.063 = 12.663 or 12.66 rounded down. Now add 3 counts. The upper range is 12.69.So for a calibrated reference 12.60, the 15B will be in specifications if the reading is between 12.51 and 12.69.edit: clarify ranges.

author: retiredcaps
author_rank: Super Contributor
timestamp: March 29, 2014, 11:29:06 pm
content: BTW, Dave talks about counts, accuracy, back in #26

author: retiredcaps
author_rank: Super Contributor
timestamp: March 29, 2014, 11:41:21 pm
content: Quote from: Zepnat on March 29, 2014, 11:05:53 pmThe specification will be 0.5% + 3 counts for a reading with 3.800V.3.800 * .005 = 0.0193.800 - 0.019 = 3.781. Subtract 3 counts. 3.781 - 0.003 = 3.7783.800 + 0.019 = 3.819. Add 3 counts. 3.819 + 0.003 = 3.822.

author: Zepnat
author_rank: Regular Contributor
timestamp: March 30, 2014, 12:01:38 am
content: ahh ha...Thank you all for your fast replies I now see where I went wrong, using the specs from the sellers website they quote1.0% +/- 10 counts,they don't mention;0 to 400mV is 1.0% +/- 10 counts (in mV range)0 to 1000V range is 0.5% + 3 counts (in V range)Also I used 0.1% in the initial calculation instead of 1% im a idiot my bad.Ill watch that video next week, no youtube at the moment due to internet provider not liking me watching daves long videos!Think I might get one here is the link if anyone else interestedhttp://www.banggood.com/Fluke-15B-F15B-Professional-Auto-Range-Digital-Multimeter-Tester-p-911684.htmlThey are ok I have bought from them before.

author: Fsck
author_rank: Super Contributor
timestamp: March 30, 2014, 12:04:09 am
content: for that price, wouldn't a UT-61E be a better choice (for electronics)?you'd get superior specs and computer logging.

author: Lightages
author_rank: Unknown
timestamp: March 30, 2014, 12:18:57 am
content: Quote from: Fsck on March 30, 2014, 12:04:09 amThe Fluke is 15B is not the fullest featured multimeter in the world but you can count on its build quality and it being safe. That is the trade off compared to the UT61E and its higher accuracy and computer logging.

author: Fsck
author_rank: Super Contributor
timestamp: March 30, 2014, 12:24:55 am
content: Quote from: Lightages on March 30, 2014, 12:18:57 ambut, it's safeness rating is still limited, but still above what typical electronics fall under.

author: Zepnat
author_rank: Regular Contributor
timestamp: March 30, 2014, 12:31:10 am
content: Quote from: Fsck on March 30, 2014, 12:04:09 amCertainly looks like it would be thanks.Is the UT-61E accurate enough to make use of the extra display resolution, having the extra digit only gives a more meaningful result if its reliable right?Do like the data logging option and for under $50 bargain!

author: Fsck
author_rank: Super Contributor
timestamp: March 30, 2014, 12:37:19 am
content: large thread on it:https://www.eevblog.com/forum/testgear/uni-t-ut61e-multimeter-teardown-photos/there are many threads about it, due it's excellent performance+features/cost ratio.

author: Zepnat
author_rank: Regular Contributor
timestamp: May 08, 2014, 10:30:48 pm
content: So, I opted for the ut-61e from a seller off aliexpress. £29 well spent. The ohms range is lightening fast also the bar graph is more useful than expected. Downloaded ultra dmm but not used in anger yet..Happy

author: miguelvp
author_rank: Super Contributor
timestamp: May 10, 2014, 07:30:21 am
content: Quote from: Zepnat on May 08, 2014, 10:30:48 pmTryhttp://sigrok.org/They seem to support your meter:http://sigrok.org/wiki/UNI-T_UT61E