Why do we want fast continuity detection in a multimeter?

[Hogwild]

Hi everyone:

Let's assume I'm a complete newbie, with next to no understanding of electronics and only basic knowledge of how to use a multimeter.

In many of the Dave's reviews, we watch him check the continuity test function of a meter by shorting the two leads and listening for how quickly the meter beeps. Faster is better, apparently.

Please help the newbie understand, why do we want faster speed doing this? Will a fraction of a second make a difference? If a meter responds slowly, is that a sign of other issues which might occur, or just poor build quality? Since continuity is the inverse of resistance, I wonder if it's a sign the meter will be innacurate with resistance tests.

I ask because I just got a Zotek ZT-Y. It seems to match the other meter I use so far for measurements, but doing that continuity test, it's definitely quite a bit slower.

[ataradov]

It is not about being faster, it is about latching the first continuity reading and producing a sound for a bit even if there is no longer continuity there. This eliminates the scratchy sound because of contact bounce.

A good meter should be imperceptibly fast, if it is slow enough to be noticeable, then it will annoy you all the time. And you will potentially be missing continuity when doing a lot of measurements (like tracing a board or a cable harness).

[Hogwild]

Hmm..yeah, that's sort of what I figured.

So, I think I may have jumped on the ZT-Y too quickly. Are there models higher up in the same line, with the same or similar LED display? I have trouble with my eyes, and very little lighting in my place. That combination made the ZT-Y very appealing to me. And I do love the display, but I'm wondering if there's something of better quality in the same line with similar great display.

[ataradov]

No idea about LED displays, but one way around this may be to use another meter for continuity, since it does not require looking at a display. Not ideal, but it is hard to guess with all the random cheap meters.

[DaJMasta]

Try using a continuity tester to buzz out traces on a board.  If it's fast, you can use one probe on the thing you're trying to find the route to and just brush the other probe on contacts as you need - along the pins of a SOP package, for example - and just hear a little noise if it makes contact.

If your continuity tester is slow, you have to try every individual pin because you need to wait to see if it sounds.  A slow continuity tester isn't just on a delay, it's actually taking that delay worth of time to decide if the continuity is there (basically just looking for a resistance measurement below a certain threshold), so if it's slower and you drag it across pins with only one actually connected to the other point, you may miss it entirely because the time the probe is on that one pin is pretty small.

Latching is a nice QoL feature, but is very much the secondary feature to me - I want it to tell me quickly so I can cover a lot of potential pins in a short amount of time.

[HKJ]

Fast continuity is very useful when tracing connections.
You can slide one probe across IC or connector pins and if any of them are connected to the place where the other probe is, the buzzer will sound. With a slow continuity you cannot do that, but have to check each pin individually and that is MUCH slower.

[Aldo22]

Reasonable speed in continuity testing does not necessarily have to be expensive.
For example UNI-T UT123
https://youtu.be/s8mRZVx4m6k?t=607

These are also available under the name VOLTCRAFT VC-22 (only in Europe?)

[Fungus]

It's like playing a piano. When you press a piano key you want a sound NOW, not in half a second.

No, it's not indicative of other problems.

[kripton2035]

you can even build one yourself , and it can even detect where a short is on  a board ...

http://kripton2035.free.fr/Projects/shorty-display.html
https://youtu.be/8mYyr9uKpFU

[nctnico]

Try using a continuity tester to buzz out traces on a board.  If it's fast, you can use one probe on the thing you're trying to find the route to and just brush the other probe on contacts as you need - along the pins of a SOP package, for example - and just hear a little noise if it makes contact.

If your continuity tester is slow, you have to try every individual pin because you need to wait to see if it sounds.  A slow continuity tester isn't just on a delay, it's actually taking that delay worth of time to decide if the continuity is there (basically just looking for a resistance measurement below a certain threshold), so if it's slower and you drag it across pins with only one actually connected to the other point, you may miss it entirely because the time the probe is on that one pin is pretty small.

Latching is a nice QoL feature, but is very much the secondary feature to me - I want it to tell me quickly so I can cover a lot of potential pins in a short amount of time.

IMHO latching is just as bad as a delay  I like the raw information (even if that means intermittent sound) because it tells me how well the probes make contact. For measurements where I want to be sure there is continuity or not, I do 3 measurements: A-A A-B and B-B while holding one probe in the same spot. That way I also know whether the probe actually made contact during the measurement.

[Hogwild]

That's a ton of useful information. Thanks. So, does anyone know whether any Zotek/Zoyi models higher in the product line have better continuity testing?

[Fungus]

I don't think the ZT-Y will be a slow meter.

The probes make a big difference. Try cleaning the points with alcohol or soap to remove grease, see what happens.

Next: Get some gold plated probes.

[TimFox]

Building on comments above:
Moving a probe along a metal trace or wire often gives an intermittent connection, depending on the state of the probe (Au plating is better) and the junk on the surface of the wire (especially solder flux and oxidation).

[BeBuLamar]

I use the resistance measurement to check for continuity normally. It would tell me how good the continuilty is. I use the contnuity function when it's intermittent and it happens to quick to take a reading.

[Hogwild]

The Pomona probes I have work very quickly with my old Mastercraft meter. They work much more slowly when connected to the Zotek. That tells me it's not the probes.

[bdunham7]

Please help the newbie understand, why do we want faster speed doing this? Will a fraction of a second make a difference? If a meter responds slowly, is that a sign of other issues which might occur, or just poor build quality? Since continuity is the inverse of resistance, I wonder if it's a sign the meter will be innacurate with resistance tests.

The continuity beeper response and the resistance ranges aren't related like that and continuity ranges typically display in ohms, although some might not.  Typically people want fast continuity so they can quickly scan a row of contacts instead of slowly poking at them.  Although there are some cases where latching is a detriment, the ideal continuity feature pack (IMO) is fast, latching (with a short signal just long enough to be definitely heard), fast bargraph action and an ohms display with multiple ranges and multiple continuity thresholds. 

Not having 'good' continuity features usually doesn't say much about the meter in general or how it might perform in other ranges.  I suppose you might think that a meter that does everything slowly might also be slow with continuity, but not always.  The Fluke 289, for example, is pretty slow to autorange in ohms and to settle in the low-ohms range but has lightning fast continuity as well as all of the features I mentioned.  A lot of these issues are design choices rather than straight up good-or-bad design.

[Martin72]

Continuity tests...
We do this nearly every day when checking the point to point connections of wired cabinets for example.
Each wire got it´s own number in the schematic and on itself, so we first check the connection on the schematic and then "beep out" the connection in the cabinet/circuit.
This takes time...
So for our purposes it is not important how fast a tester react.
Mostly we turn off the beeper (and watching the display instead)because if you test a cabinet it could last 1..2hours or more and then the sound could be very annoying.
PLUS: There is a kind of threshold when the meter will beep - Most of the meters will beep under a specified resistance value.
Not when the connection is "zero" ohms.
So if you got lower value resistance connections in the circuit and test the connection only via beep, you won´t know if this connection is right.

[mwb1100]

As far as other Zotek meters, I have a ZT-301 that has a perfectly fine continuity buzzer.  It doesn't have the same kind of display as the ZT-Y, but the ZT-301 has a backlight that stays on for 15 minutes (essentially, the ZT-Y's display is backlit all the time which is one of the things that gives it a highly readable display).

Also keep in mind that many (most?) Aneng meters are Zotek rebrands, so you can get an idea of the continuity performance from the hundreds of reviews of Aneng's various meters on the web.  I believe all of the hugely popular Aneng AN8000 series are Zotek built.

Another thing to consider is keeping the ZT-Y that you like and getting a cheap second meter for times when you need/want the quick continuity (note that even though the ZT-Y doesn't seem have top-of-class continuity speed, it's not too bad in my opinion).  Plus then you have a second meter for whatever (a go bag, to be able to do current on one and voltage on another, etc.). A super cheap meter that has instantaneous continuity buzzer:

  - Mastifuyi FY77 which is less than $10 right now on Amazon US (with a coupon you have to select)

Keep in mind that I generally replace my cheap meter's probes with something better - you might need to do the same with the FY77 - I don't remember if the probes that came with it had delayed continuity

Also, don't use something like the FY77 on mains - keep it to low voltage electronics.

[Brumby]

You want fast detection and only enough latching for you to hear a beep.

This is most helpful in the situations where you are testing a lot of points.

For example:

Fast continuity is very useful when tracing connections.
You can slide one probe across IC or connector pins and if any of them are connected to the place where the other probe is, the buzzer will sound. With a slow continuity you cannot do that, but have to check each pin individually and that is MUCH slower.

If you swipe along 20 contacts in half a second, you will want fast response so that you don't miss any hits.  It's really useless if you actually have continuity and the meter is so slow that it didn't have time to tell you before you moved on!
As for latching - you only need that to be long enough so that you hear the beep.

Certainly, when "sliding" your probe may have moved on from the target connection by the time the meter sounds and you respond (don't forget that) but once alerted, you go back and double-check the last few points to positively determine the winner.  It's at this stage you can check the actual ohms.

This is the process I use in my efforts as a hobbyist and (from my observation) so do a great many.  Nevertheless, there will be those that do continuity testing at the professional level that will have developed a finer sense and more polished processes with more specific requirements that may be necessary for particular situations, but the above is certainly adequate for common usage - IMO.


I find Dave's test for speed and latching on a meter very useful.

[Fungus]

If you swipe along 20 contacts in half a second, you will want fast response so that you don't miss any hits.  It's really useless if you actually have continuity and the meter is so slow that it didn't have time to tell you before you moved on!

I don't recall ever doing that so it wouldn't be something I'd lose sleep over, but... 

The Pomona probes I have work very quickly with my old Mastercraft meter. They work much more slowly when connected to the Zotek. That tells me it's not the probes.

The Pomona probes I have work very quickly with my old Mastercraft meter. They work much more slowly when connected to the Zotek. That tells me it's not the probes.

I don't have that exact model Zotek so I can't really comment but none of the ones I have are unusably slow.

Whatever: If you ever find yourself zipping down long rows of pins you can use your Mastercraft.

There's no such thing as a perfect meter. Everybody here owns dozens of meters and has a favorite for each job. 

[floobydust]

I use older DMM's that use an analog comparator (no MCU involved) for the continuity detect.
This gives lightning fast response which is invaluable if you are looking for a bad connection. Wiggling things you can "hear" the scratching sound of the bad connection and find it FAST. Is it the cable, the connector, the switch etc., you can find right away.
Not so with these sluggish MCU-involved DMM's.

[Fungus]

Wiggling things you can "hear" the scratching sound of the bad connection and find it FAST. Is it the cable, the connector, the switch etc., you can find right away.

Yep. People often complain about the "bad sound" of the scratchy ones sound but they give more info.

[CatalinaWOW]

I agree with the many prior posts that say that fast is good.  I have seen no specific statements about how fast is good enough.  I am sure that everyone's opinion on this will vary, but to give the OP something to work with I will mention what I think the numbers should be.

Human reaction time to a sound or other stimulus is a few hundred milliseconds, with many variable involved.  So times faster than two or three hundred milliseconds are probably not discernable by everyone, and not of major benefit to anyone.  The possible exception to this is the sweeping over a connector example, where a faster time would allow you to more quickly determine that a pin somewhere in the connector was connected.  But even in this case a slower, human limited scan would be needed to find the specific pin.  Maybe a half interval search would still benefit from the faster time, but that isn't an approach that many will use.

I have become very impatient with a couple of meters that I have owned that have reaction times in the one or two second or longer time frame.  To the point that those meters are no longer in the active stable.  So response times under a second are desirable.

I will also point out that those who don't prefer to use a beeper for continuity and just watch the meter are forced to be relatively slow and methodical because it isn't possible for most people to place a probe and watch the meter at the same time.  In many situations it is difficult to place the probe (and keep it from touching things it shouldn't) without watching continuously.  The beep is invaluable in these situations.

[Fungus]

I agree with the many prior posts that say that fast is good.  I have seen no specific statements about how fast is good enough.

It's very subjective and will depend on what you use your meter for.

eg. I already said I never find myself zipping down connectors. I guess the people who "zip" are trying to figure out unknown PCBs which is something I never really do. I mostly build my own stuff so 99% of the time I know where the probes are supposed to go,  I'm just checking for bad connections and/or short circuits.

I own very fast meters but I wouldn't say it's life or death for me.

[BeBuLamar]

I agree with the many prior posts that say that fast is good.  I have seen no specific statements about how fast is good enough.

It's very subjective and will depend on what you use your meter for.

eg. I already said I never find myself zipping down connectors. I guess the people who "zip" are trying to figure out unknown PCBs which is something I never really do. I mostly build my own stuff so 99% of the time I know where the probes are supposed to go,  I'm just checking for bad connections and/or short circuits.

I own very fast meters but I wouldn't say it's life or death for me.

I actually rarely ever used the continuity feature. I almost always use the resistance measuring function. But sometimes I use the continuity to troubleshoot an intermittent connection and when it breaks it breaks very briefly.