Multimeter to measure resistance and continuity simutaneously? - Page 1
Forum section: electronics / testgear

author: Valver
author_rank: Contributor
timestamp: March 18, 2019, 07:07:14 pm
content: When tracing out a circuit board I find that I am constantly switching between resistance and continuity modes, not to mention having to skip over the diode check and capacitance functions to get back to the original resistance setting. Does there exist a multimeter that can measure resistance and also beep when there is a short? In other words combine resistance measurement and check for continuity without having to change setting on the meter?

author: HKJ
author_rank: Super Contributor
timestamp: March 18, 2019, 09:17:22 pm
content: Brymen BM27s can do that, but it is VERY slow because ohm mode first needs to range down to the lowest mode, before it will detect low resistance and beep.

author: Valver
author_rank: Contributor
timestamp: March 18, 2019, 09:39:21 pm
content: Quote from: HKJ on March 18, 2019, 09:17:22 pmHey, that's a good start. I didn't think I'd actually be able to find one. Pity that it's so slow, but I can't complain about the price and I like it's simplicity. I don't use my Brymen (BM235) for continuity however because I can't hear the beeper unless I close the windows (and turn off the music, lol)Hopefully this meter is louder.Thanks for the reply, it's worth checking out.

author: HalFET
author_rank: Frequent Contributor
timestamp: March 18, 2019, 10:07:11 pm
content: Keysight U1232A also measures resistance when you put it into continuity mode, but it's not brilliant as a continuity checker.

author: DaJMasta
author_rank: Super Contributor
timestamp: March 18, 2019, 10:10:27 pm
content: What kind of resistance do you need to measure?My BM867s shows you the resistance in continuity mode, but it's limited to something like 100 ohms in continuity mode because it stays on the lowest resistance range. Maybe a meter that you could configure the regular resistance range to beep under like 10 ohms or something? The autoranging will be the killer for speed.... which is usually why continuity mode is its separate setting, so the beep can be responsive enough to be usable.

author: Valver
author_rank: Contributor
timestamp: March 18, 2019, 10:32:30 pm
content: Quote from: HalFET on March 18, 2019, 10:07:11 pmI was hot to get a Keysight meter for a while, partly because the AC voltage function is AC-coupled, which I need for the work that I do. After watching Joe Smith's review, however, I reconsidered. Good to know that it does this, I'll keep it in mind, thanks.

author: Valver
author_rank: Contributor
timestamp: March 19, 2019, 12:05:09 am
content: Quote from: DaJMasta on March 18, 2019, 10:10:27 pmHmm, true, that explains why it's not a common feature. Basically, I repair musical instrument tube amplifiers. I need this feature when I don't have schematics and need to trace out the circuit. I tend to switch back and forth between resistance ranges to measure components, and continuity to check for ground connections (as an example). Sacrificing a bit of speed is still faster than dropping the probes to switch functions on the meter, especially when you have to do it thirty or forty times.The Brymen BM867 is a wonderful meter, but I simply can't see the decimal point on the display without leaning over close to the meter. This is somewhat dangerous when you have both hands in an amp running at 500V. Same thing with the AC or DC symbols on the voltage ranges. Since the meter defaults to the last used setting you never can be sure what it's set to when you switch to voltage... drives me crazy. I much prefer the UNI-T 181A as far as displays go. Also, I only ever measure voltage and resistance, I never need the current, temperature, frequency, or capacitance ranges because I have LCR meters, IR gun, clamp meter, and four other multimeters that do all this.

author: joeqsmith
author_rank: Super Contributor
timestamp: March 19, 2019, 12:53:41 am
content: I have looked at a few with AUTO mode, the last being the Brymen BM27 pocket meter. I am working on a followup video for this meter.

author: vk6zgo
author_rank: Super Contributor
timestamp: March 19, 2019, 01:17:48 am
content: I think you have a non-problem.In analog days, "continuity testers" were confined to checking cables & the like.Looking for continuity in circuit, the Ohms range was used.OK, it's a bit easier with an analog meter, as if the needle swoops down to the zero Ohms end of the scale, you can generally take it as read that there is a very low resistance connection.My old Fluke 77 DMM auto ranges fast enough for me to look at normal circuit resistance values, as well as very low resistances like direct ground connections.IMHO, the continuity "beep" is a crutch---- you shouldlookat the display in Ohms range to get a real idea of how good the "continuity" is.Many continuity tests beep "OK" at relatively high resistance values.These might not matter in many cases, but in others, could be critical.For instance, if the cathode of a tube was intended to be returned to chassis, the continuity tester may beep "OK" if there is a dry joint of around 30 Ohms.This constitutes an unbypassed cathode resistor, which could mess with the bias, & definitely will cause degeneration.

author: DaJMasta
author_rank: Super Contributor
timestamp: March 19, 2019, 03:04:46 am
content: Here's an odd potential solution: a bench meter.Bench meters can have larger/higher contrast displays and you can find a lot of variants with very fast measurements or very fast autoranging. Still more, you can find many which can run scripts or simple programs - something like adding a beep to a regular resistance mode and retaining the autoscaling.Elaborate, maybe, and probably more expensive, but it could be a powerful option.

author: Fungus
author_rank: Super Contributor
timestamp: March 19, 2019, 03:06:37 am
content: Quote from: Valver on March 18, 2019, 07:07:14 pmHere's three:https://www.eevblog.com/forum/testgear/weird-new-aneng-multimeters-hybrid-design/

author: HKJ
author_rank: Super Contributor
timestamp: March 19, 2019, 05:01:42 am
content: Quote from: Valver on March 18, 2019, 09:39:21 pmThe reason it works is because it has a AUTO everything mode and it is not really a simple meter, the ranges is on the confusing side.Another meter with a auto everything range is Peakmeter MS8248s, it can also do it and is also slow, but faster than the Brymen (It is not really a good meter). There is also the Aneng V01A, again a auto everything meter.

author: bugi
author_rank: Regular Contributor
timestamp: March 19, 2019, 08:24:50 am
content: Quote from: Valver on March 19, 2019, 12:05:09 amWhile I do similar task for just curiosity over random pieces of equipment (except PC PSU's, some of which I tried to repair), I've solved this problem by doing things in two steps: first trace the connections, just drawing components without values (or with nominal values if/when visible). Once done with that, I switch to resistance mode (or capacitance etc.) and measure the component values... or thereabouts, since in-circuit measurements can of course be a bit tricky. Thus, no need to be constantly switching between modes.My solution might have been affected by using a really crappy DMM for years, and later limited myself to buy a single good DMM (ended with BM867s), and living with the compromises of that particular choice.

author: jfiresto
author_rank: Frequent Contributor
timestamp: March 19, 2019, 09:17:15 am
content: In continuity mode, the B&K Precision 390A will beep at or below 40 ohms and show the resistance up to 400 ohms, within 100 ms with a distinct squeal. Pressing the SHIFT button cycles over continuity, auto-ranging resistance and diode voltage modes, so at least you won't hassle with and wear out the large, meter mode switch. IIRC, the continuity mode, data logging stream was also sensible.

author: dzseki
author_rank: Frequent Contributor
timestamp: March 19, 2019, 11:05:36 am
content: The very cheap chinese manual 3 1/2 digit DMMs have the diode and beep mode combined. In this mode they source 1mA current for the diode, but obviously useful for measuring resistances to up to 2k Ohms and they beep under 10 Ohms or so FYI.

author: joeqsmith
author_rank: Super Contributor
timestamp: March 19, 2019, 12:02:55 pm
content: This meter from Klien was my pick for the first set of $50 meters I looked at. It also has an AUTO mode but it seems it could not read very high resistance values. It was made for electricians as a backup meter. Mechanically, it IS the toughest meter I have looked at. Electrically, it's not so tough.https://www.kleintools.com/content/how-tough-your-meter

author: shteii01
author_rank: Frequent Contributor
timestamp: March 19, 2019, 12:08:44 pm
content: Use two meters.

author: joeqsmith
author_rank: Super Contributor
timestamp: March 19, 2019, 12:42:45 pm
content: Quote from: shteii01 on March 19, 2019, 12:08:44 pmI may be faster for them to change modes than keep track of leads.I have a very old Fluke 97 scopemeter that will also do what you want. Maybe their newer scope meters support this as well.

author: Valver
author_rank: Contributor
timestamp: March 19, 2019, 12:57:40 pm
content: Quote from: joeqsmith on March 19, 2019, 12:53:41 amSir, you truly are a champion to the cause.

author: Mortymore
author_rank: Frequent Contributor
timestamp: March 19, 2019, 01:28:15 pm
content: Fluke 83 and 87 do it. 85 should do it too.When the continuity mode is selected, the meter jumps to a manual scale 400Ohm, but if RANGE (auto range) is pressed after that, the multimeter works as an autorange ohmmeter, beeping if resistance is lower than 400 Ohm (there's some hysteresis).PS: Amprobe AM-530-EUR doesn't have the same ability, even though it has continuity on the same position of Ohm like Fluke83...87. Once continuity is selected, the RANGE button is disabled.

author: Valver
author_rank: Contributor
timestamp: March 19, 2019, 01:52:50 pm
content: Quote from: shteii01 on March 19, 2019, 12:08:44 pmLol, I'm already using three meters at once, one on the high voltage, one to monitor output tube current, and another to measure various voltages and potentiometer values, etc. If that's not enough I need a fourth one to check the ripple current on the supply caps and negative bias because none of the three meters that I bought last year are AC-coupled so they can't detect AC signals when there is a DC component. Unfortunately I wasn't aware of this when I bought these meters. I need to replace the fourth meter, so now I'm naturally a bit more cautious before buying something else.I know someone will suggest a dual display meter, but the AC resolution is too poor when using the 600V or 1000V DC range. This requires changing the function to AC measurement for better resolution in the millivolt range, so there's no advantage over using an AC-Coupled meter and switching between AC and DC modes. Thanks again to Joe Smith for the tests that he performed regarding this.

author: Valver
author_rank: Contributor
timestamp: March 19, 2019, 04:28:38 pm
content: Quote from: Fungus on March 19, 2019, 03:06:37 amVery interesting, what a deal! I'm a sucker for that EBTN screen display. Free shipping to Canada as well! 250v fuses but I never measure current. I'll research it a bit.Thanks!

author: Valver
author_rank: Contributor
timestamp: March 19, 2019, 05:00:02 pm
content: Quote from: Mortymore on March 19, 2019, 01:28:15 pmThat's an intelligent feature, is this even documented? I've been checking the user manuals for the 87V and don't find mention of this.

author: joeqsmith
author_rank: Super Contributor
timestamp: March 19, 2019, 05:00:57 pm
content: Quote from: Mortymore on March 19, 2019, 01:28:15 pmGood info. My 189 allows the manual range but not auto. The threshold obviously changes with the range. My 97 is a bit different. There is no separate continuity mode. You just enable the audio.

author: joeqsmith
author_rank: Super Contributor
timestamp: March 19, 2019, 05:13:03 pm
content: Quote from: Valver on March 19, 2019, 01:52:50 pmI was never sure what your requirements were but I'm glad you found it helpful. FYI, I did try this out on the last meter I looked at.https://youtu.be/4aCN-uLeO5s?t=3162

author: Mortymore
author_rank: Frequent Contributor
timestamp: March 19, 2019, 05:13:51 pm
content: Quote from: Valver on March 19, 2019, 05:00:02 pmI didn't read the manuals (not now, I mean).When I went home, made a test on some meters that might work accordingly to your request. So I tested a Fluke 83 and 87 (1st series) and 87III. I don't have any of the series V.EDIT: About the hysteresis, what I mean is that the "beep" is enable until some 250 Ohm, if the resistance is rising. But if it come from high Ohm, to low, it only beeps when lower below 100 Ohm or so.

author: rsjsouza
author_rank: Super Contributor
timestamp: March 19, 2019, 05:33:15 pm
content: Most (if not all) the meters I have do fixed range ohms measurements (typically up to its maximum number of counts) while in continuity mode: Keysight U1282A, U1273A, Samwa PM300 (Dave sells it in his store), Uni-T UT136C/UT61E/UT139C, Brymen BM857, etc. This is done without loss of the beep speed, but obviously the actual measurement is a bit slower. Also, the beep threshold varies a lot, with some limiting this to 20Ω and others to 50Ω.

author: Fungus
author_rank: Super Contributor
timestamp: March 19, 2019, 09:15:06 pm
content: Quote from: Valver on March 19, 2019, 04:28:38 pmNow that I look closer, I'm not sure the one with the weird display has a fully "auto" range. The other two do.

author: Valver
author_rank: Contributor
timestamp: April 06, 2019, 11:48:43 am
content: Quote from: rsjsouza on March 19, 2019, 05:33:15 pmI've tried unsuccessfully to do this with my UT61E, UT139S, and Brymen 235. How did you achieve this?

author: Valver
author_rank: Contributor
timestamp: April 06, 2019, 12:35:08 pm
content: Quote from: Fungus on March 19, 2019, 09:15:06 pmOk, so I bought the one with the weird display (Anang V8). Arrived yesterday from Banggood. No, doesn't have a full Auto feature, but i bought it for the display.Amazing looking display, much better than the UNI-T 139S which also has a reverse screen display. Runs on three batteries so the contrast is excellent. Fast update speed, feels really peppy. Good fast continuity range with a loud beeper and a light light that flashes also. Makes my other meters look obsolete.I'm having an RF interference issue with it however. I'm in an extremely strong RF zone and have to deal with it all the time. Moving test leads (good ones) around while measuring a voltage can cause an appreciable fluctuation in (DC) voltage reading. I suspect that this may simply be because of the meter's 20 Meg bandwidth. My other meters have no RF issues and all have very limited bandwidth. Too soon to reach any conclusions.

author: Fungus
author_rank: Super Contributor
timestamp: April 06, 2019, 02:31:10 pm
content: Quote from: Valver on April 06, 2019, 12:35:08 pmIs the display evenly lit now?Be sure to find out how the display does with decreasing battery voltage. The ANENG Q1 has a similar display that does really badly, see Dave's video at 8:45:nb. If yours has three batteries then it might be solved.

author: frozenfrogz
author_rank: Frequent Contributor
timestamp: April 06, 2019, 02:55:45 pm
content: Fluke 8060A has that feature. You can switch on continuity via soft-button in every range.

author: Valver
author_rank: Contributor
timestamp: April 06, 2019, 03:28:00 pm
content: Quote from: Fungus on April 06, 2019, 02:31:10 pmDisplay is sublime! No comparison with these others, really good contrast. Viewing angle is very good from below and sides but is limited from above. Battery life? Well, probably not so good.

author: Fungus
author_rank: Super Contributor
timestamp: April 06, 2019, 04:23:17 pm
content: Quote from: Valver on April 06, 2019, 03:28:00 pmPhotos?Is it evenly lit or can you see where the individual LEDs are? Do you have a power supply so you can do a similar test to Dave?(It's much faster with a power supply than waiting for the battery to die)Power consumption?I imagine having 4.5V instead of 3V makes all the difference, but we like to measure....

author: Valver
author_rank: Contributor
timestamp: April 09, 2019, 02:47:58 pm
content: OK, I checked it out some more. Current consumption is 25ma, pretty much what I expected. Display is uniform, no unevenly lit areas, has one single completely dead angle only when viewed from the top. Plastic screen seems to scratch simply by looking at it.I removed one of the three (alkaline) batteries in order to operate the meter at 3V. Display was dimmer but still bright enough in regular daylight (not direct sunlight). In fact it was brighter than the UNI-T 139S which has a similar display. All very acceptable. In real usage I would imagine that batteries would need to be replaced when they are at 1.25V, 1.2V if you're lucky.

author: rsjsouza
author_rank: Super Contributor
timestamp: April 09, 2019, 04:24:47 pm
content: Quote from: Valver on April 09, 2019, 02:47:58 pmWow, that is pretty close to the U1273A (OLED display).Joe and I listed some power consumption measurements at:https://www.eevblog.com/forum/testgear/hear-kitty-kitty-kitty-nope-not-that-kind-of-cat/msg2084320/#msg2084320https://www.eevblog.com/forum/testgear/hear-kitty-kitty-kitty-nope-not-that-kind-of-cat/msg2100013/#msg2100013

author: Fungus
author_rank: Super Contributor
timestamp: April 09, 2019, 05:08:58 pm
content: Quote from: Valver on April 09, 2019, 02:47:58 pmNo boost converter then. Bummer.Quote from: Valver on April 09, 2019, 02:47:58 pmThat's still only ~50% of the usable capacity of a battery.Quote from: Valver on April 09, 2019, 02:47:58 pmBy my math your average alkalines should last about 40-50 hours. That's not great. Heavy users should definitely be looking at rechargeables.(...you could probably get double that with Batteroo!)