Multimeter that shows AC and DC at the same time - Page 1
Forum section: electronics / testgear

author: rccola777
author_rank: Newbie
timestamp: November 27, 2018, 03:58:00 pm
content: I was recently watching a video from The Signal Path and he was using a Fluke 289 and while measuring a dc voltage it was also showing any ac ripple at the same time. This is something that would be very useful to me. Are there any meters that do this in a smaller form factor than the 289?

author: DaJMasta
author_rank: Super Contributor
timestamp: November 27, 2018, 04:04:07 pm
content: I think the Brymen867s/869s are smaller and they do it, but they are certainly not smallNot an uncommon feature if the meter has a dual display - the 121GW does it and is quite small for its performance/features.

author: PTR_1275
author_rank: Frequent Contributor
timestamp: November 27, 2018, 04:09:57 pm
content: Keysight u1252b has the dual display too.Can be set to display quite a few different parameters.

author: CDaniel
author_rank: Frequent Contributor
timestamp: November 27, 2018, 05:16:39 pm
content: Quote from: DaJMasta on November 27, 2018, 04:04:07 pm121GW is showing only DC+AC on primary display , it could display both but they didn't do it .For every meter you have to read carefully the specs , dual display is not a guaranty that it will show both DC and AC .

author: joeqsmith
author_rank: Super Contributor
timestamp: November 27, 2018, 05:53:11 pm
content: Quote from: rccola777 on November 27, 2018, 03:58:00 pmOf the meters I have looked at, the following support it.Fluke 189Fluke 97 scope meterUNI-T UT181A (Fluke 289 clone)TPI 194II (made by Summit)Brymen BM869sThe Extech EX540 / CEM DD9939 with it's tri-display does not support it but it does have AC+DC. I am not sure about the Gossen Ultra. You would need to check.****A bit strange that the most expensive handheld meter I have, the Gossen, doesn't support it.

author: HKJ
author_rank: Super Contributor
timestamp: November 27, 2018, 06:33:37 pm
content: Brymen 525s can do it, both AC+DC and DC,ACUNI-T UT195DS can sort of do it, it will show AC+DC on main display and toggle between DC and AC value on secondary displayProva 903 is two meters and dual readout, using them in parallel with on on AC the other on DC would do the trick.AC+DC is usual used about sqrt(sqr(VAC)+sqr(VDC))Bench meters can also show DC,AC, but it will usual include a relay toggling inside the meter.I used my review index and checked meters with dual displal, I skipped all them that is listed above.https://lygte-info.dk/info/DMMReviews.html

author: Fungus
author_rank: Super Contributor
timestamp: November 27, 2018, 08:36:57 pm
content: Hioki DT4282:https://www.hioki.com/en/products/detail/?product_key=5570

author: Specmaster
author_rank: Super Contributor
timestamp: November 28, 2018, 07:52:39 am
content: The Brymen 867 also does both AC and DC at the same, it is basically a 869 without the temperature range.

author: 001
author_rank: Super Contributor
timestamp: November 28, 2018, 08:10:59 am
content: sorry for offtopIs DSO a way to read AC+DC correctly?

author: Performa01
author_rank: Super Contributor
timestamp: November 28, 2018, 10:58:58 am
content: Quote from: 001 on November 28, 2018, 08:10:59 amYes it is in principle, as long as it can provide Cycle RMS (for AC+DC RMS), Cycle Stdev (for AC RMS) and Mean (for DC) measurement functions.Yet DSOs aren't meant to be precision instruments, and the majority of them is 8-bits only, hence the resolution is limited to some 0.5%.

author: Fungus
author_rank: Super Contributor
timestamp: November 28, 2018, 11:52:50 am
content: Quote from: Performa01 on November 28, 2018, 10:58:58 amI think you might be off by an order of magnitude.

author: perieanuo
author_rank: Frequent Contributor
timestamp: November 28, 2018, 12:16:52 pm
content: + Chauvin Arnoux CA5275 &co, less than 100 euros in perfect state in franceEnvoyé de mon iPad en utilisant Tapatalk

author: hgjdwx
author_rank: Regular Contributor
timestamp: November 28, 2018, 12:44:48 pm
content: Quote from: Fungus on November 27, 2018, 08:36:57 pmUnfortunately, DT4282 millivolt range does not have dual display. And only the voltage AC+DC, no current AC+DC

author: Floopy
author_rank: Regular Contributor
timestamp: November 28, 2018, 02:43:17 pm
content: My Fluke 189 does it and it's great. Especially when you don't know if a voltage is AC or DC.

author: DaJMasta
author_rank: Super Contributor
timestamp: November 28, 2018, 02:49:26 pm
content: Quote from: Fungus on November 28, 2018, 11:52:50 amYeah, spec is typically 2-3% accuracy at best, maybe a 10 or 12 bit scope could be a bit better, but as mentioned, they're for showing precision time, not precision voltage.

author: Performa01
author_rank: Super Contributor
timestamp: November 28, 2018, 02:59:46 pm
content: Quote from: DaJMasta on November 28, 2018, 02:49:26 pmMind you,resolutionis something different thanaccuracy.And 0.5% resolution means just +/-100 counts or 2 digits, which cannot compete even with the cheapest handheld DMM - that's what I was referring to. For 3-1/2 digits, we need 12 bits indeed.

author: joeqsmith
author_rank: Super Contributor
timestamp: November 28, 2018, 03:24:31 pm
content: DMMs typically don't have much bandwidth. They do make some decent scopes with lower BW, higher resolution and better accuracy. I think that Hioki I showed is 0.1% accuracy for voltage which is still not all that great. I think it was using multiple 16-bit delta sigma convertors. Not suggesting it's a generic bit of equipment. Far from it. But a scope with some decent specs certainly could be designed if they are not available already.

author: coromonadalix
author_rank: Super Contributor
timestamp: November 29, 2018, 02:59:34 am
content: +1 for the Fluke 189

author: joeqsmith
author_rank: Super Contributor
timestamp: November 29, 2018, 03:10:02 am
content: Maybe Fluke will come out with theirClassic Line. Fluke 189, 187, 87IV (all made in China.).

author: helius
author_rank: Super Contributor
timestamp: November 29, 2018, 05:22:29 am
content: I recently added a Yokogawa TY710 to the collection. It has simultaneous DC , AC display on the DC volts position, and the current positions.

author: hgjdwx
author_rank: Regular Contributor
timestamp: November 29, 2018, 06:44:49 am
content: Quote from: Floopy on November 28, 2018, 02:43:17 pm189 can't do well, it's V and mV is separate, and in dual mode it use the same range of AVC and DCV, this makes the area is different from that of ACV and DCV listed (e.g., measurement of dc power supply ripple) the resolution of the small voltage is not enough, such as measuring a 60 V power supply ripple, ACV and DCV will use 500 V range at the same time, listed clearly for dozens of millivolt ripple, 500 V range is too big

author: John B
author_rank: Frequent Contributor
timestamp: November 29, 2018, 07:44:16 am
content: Just a note on the Brymen though, when making simultaneous AC and DC measurements, the update rate slows considerably. So only suitable for steady measurements.

author: plurn
author_rank: Regular Contributor
timestamp: December 06, 2018, 04:32:21 am
content: keysight/agilent u1272a does the dual display AC, DC. It does the equivalent of RMS AC ripple - not peak to peak.It does not auto range each one individually though - they would both be in the same range. So if you want more accurate ripple, setting it to a mV range for example the DC might be out of range and not display.TRXBench youtube video where he shows it in action and compares it to an oscilloscope. RMS reading is quite close between the two.https://youtu.be/OH6U2SKQaOw?t=2127