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  • Multimeter recommendations

    Hi,

    You might know me from my website at Guitar Wiring Site

    I already have a pretty good digital meter for measuring voltage, current and resistance.
    Anyway, for about 5 years I had a Sinometer (purchased for $50) which I used for measuring inductance and capacitance but it finally died. It measured inductance from about 100 microhenrys to 20 Henrys and capacitance from about 100 pf to 20 mfd.
    Since I'll have to buy another multimeter, I'd want the inductance and capacitance ranges to at least be the same. The Sinometer's ability to measure inductance was pretty bad especially in the 1 to 20 Henry range. (Yes, those are pretty high values but for guitar players it is what you need for measuring wah inductors, tone control inductors and especially pickups)

    I'd like just to get an inductance / capacitance (LC) meter but it seems those are getting scarce so I'd be willing to buy an LCR meter. What I really want is accuracy. I don't know if True RMS is necessary for extreme accuracy for measuring passive components, but if so, I'd be willing to spend maybe $150.
    I'd like to think I could get buy with another cheap meter but that Sinometer could get very inaccurate.
    Any multimeter suggestions?

  • #2
    You might be a candidate for a Sencore Z-meter. The LC series. They have been making LC Z-meters for many years, and every so often they update the design and so on. But the basic measurement of caps and inductors doesn't rely on bells and whistles. SO an older one would work fine for you. It is a cap and inductor analyzer, so in addition to measurement, it also checks leakage AT VOLTAGE, and such things as ESR.

    Looks like they are up to LC103 these days. Brand new, Sencore stuff is stupidly expensive, but you can find older used pieces.

    It is not a hand-held, it sits on the bench. it is about the size of a lunch box.

    Just google up Sencore Z meter. Maybe pricier than you want even used, but worth a look. This is the sort of thing you might find a deal on at local amatuer radio "ham fests."


    But if that isn;t of interest, a word about modern test gear. You mentioned wanting only an LC meter, but would settle for LCR. The thing inside all these is pretty much the same. it costs them virtually nothing to add features to their meter products because the same guys can do it. So they do. HAving an LC meter that also measures resistance doesn;t make it less of an LC meter. But having the extra function makes their meter more attractive to the general market than one lacking features. So you see DMMs these days including frequency counters, cap meters, transistor hfe measures, and who knows what else. As far as the meter guts are concerned, it is just an extra stop on the selector switch.

    RMS refers to a varying voltage waveform measurement. There is no such thing as RMS resistance, capacitance, or inductance. A multimeter that has your measuring functions for L and C could also include voltage. If it did, then RMS would apply to the AC voltage readings. ASking for a true RMS capacitance meter would be like asking the grocer for a metric tomato.


    Now there ARE impedance meters - impedance being the AC analogue to resistance. They use an AC current to make their measurements. ANd typically they provide a selection of frequencies. This is more likely found in a speaker tester. I could see how making puckups one could find that interesting. But that would probably be a mopre advanced piece of gear than you are interested in.
    Education is what you're left with after you have forgotten what you have learned.

    Comment


    • #3
      Funny this should come up now. I am really in need of a ESR meter for caps. I have an excellent Fluke 189 multimeter for measuring uF but i need something that will test ESR. I just had an amp that wouldn't come out of protect. the famous TA7317P problem. several post's reported that the AC detect 1uF cap goes bad. well I tested it in circuit and it measured 1uF so i figured ti was plenty good. still wouldnt come out of protect. much hair pulling and cussing, I finally pulled the 1uF and the 22uF discharge cap out of circuit and tested them, both within 5% of rated value. but...I replaced them anyway.. and lo and behold CLICK the damn thing came out of protect! SO, lesson learned.

      Looking at the used Sencore stuff. yes they are stupid expensive used. even the older LC53 is bringing $200-400

      a used HP is about 3-4 times the price of the sencore stuff!

      I found M3 Electronix, they have a cool transistor analyzer kit and now have a very cool LCRZ kit as well. not exactly cheap at $175 and frankly it looks a bit complicated to use. M3 Digital LCRZ Meter

      Then there is something like this
      GME Technology 236 Capacitor Tester In-Circuit ESR & DCR GME Technology 236
      which looks very simple to use but at $160 on eBay the M3 is the better value.

      which all this gets me thinking. I already have a very good DVM and i have a good signal generator. I wonder what would be required to build some sort of test jig to measure ESR using what I already have?

      anyone have any other options? a nice sub $100 ESR meter would be ideal

      Comment


      • #4
        All-in-one meters are a nice thought, but I haven't found one yet that can do it all well, so in addition to the Flukes we have that handle the bulk of the work, I also have a Wavetek Meterman LCR55 for routine LCR work. It also functions as a milliohmmeter, so it is great for finding shorts and has a transistor tester built-in. For e-lytic caps, I purchased this cheap Elenco CM-1555 Capacitance Meter which is the best $43 we ever spent. It accurately checks caps up to 20,000uF. We don't use transistor testers too often except mostly for matching purposes, but I have an old B & K 520B that is always on the money. In all, the three aforementioned piece won't cost more than about $350 total (minus the transistor tester, a mostly-unneeded luxury). Then there's the Simpson 260.

        There's a lot of fancy stuff out there, but for the most part, it's a lot of it collects dust and is just for wankin' e.g. the Huntron Tracker, which is also an expensive mutha, like Sencore products. My favorite old Sencore product was their Stereo Analyzer. When all is said and done, a good multimeter and experience has it over all the toys.
        John R. Frondelli
        dBm Pro Audio Services, New York, NY

        "Mediocre is the new 'Good' "

        Comment


        • #5
          zero cool

          I while ago I built one of the Dick Smith Kit ESR meters.
          They also are a low ohms meter which is handy.
          Although Dick Smith no longer stock kits as I understand it the kit has evolved
          and now available via AnaTek.
          Its interesting to test different brands of the same value.
          Some cheap looking ones I have found to have better ESR than known brands !

          Compare ESR Meters
          Ana Tek Corporation
          "Blue" ESR Meter
          Ana Tek Corporation

          Recommendations from AnaTek "If cost is paramount and you want a quality instrument then the Blue ESR kit is for you. If you want an assembled unit with a digital readout for tracking down low grade shorts then the assembled Blue ESR or the Atlas ESR60 are excellent choices. If you are partial to analog meters or want the most accurate ESR meter available (see accuracy comment above) then the Capacitor Wizard should be your choice. Avoid the other two."

          Blue ESR/Low Ohms Kit battery not included $79.00

          another reference

          Print Page - ESR meter kit

          from Steve "I think everyone knows from my previous rants that as a synth tech I just replace old electrolytics on sight in synthesisers, they are a pernicious scourge. I can understand leaving them is some good quality pro audio gear, but I would test them anyway. So instead of being the Electrolytic Soup Nazi I am going all new age and building an ESR meter kit."

          Amarbir built a kit

          The ESR Meter - Whats This Used For ? - Lynx - The Community Forums

          And more info from the designers home page

          ESR meter page

          Comment


          • #6
            Well it seems I found an interesting link right at this forum posted by Joe Gwinn:
            http://music-electronics-forum.com/t5006/
            He mentions the Extech 380193 as being the test meter he uses.

            Looking at the specs, I'd say the ranges are quite good for working on parts found in guitars.
            Looking for this meter, the price is close to $200 and so I was wondering if this cost is necessary for accuracy?
            As I've said the $50 Sinometer was terrible at measuring inductors in the 100 mH and above range. Just as an example, a pickup I tested with a published inductance of 8 Henrys tested in the Sinometer at about 18 Henrys.
            So I really don't want 5 decimal place accuracy, but is it necessary to spend $200 to get a meter that might show readings that are within 5% of the actual value?

            Comment


            • #7
              The thing that is confusing is that some of these LCR meters will measure uF and resistance but they don't state if they test ESR? I don't think they do. I think the Anatek kits is probably the best deal. but im still looking.

              Comment


              • #8
                I'm unaware of Multimeters with ESR testing as a feature.
                Because of the extra componentry, osc etc and demand, can't see one
                in the foreseeable future although I'm often surprised these days !

                Comment


                • #9
                  I appreciate all the replies to my initial posting but I really just want some fundamental information.
                  Basically, all I want is a meter that can measure inductance (100 micro-Henry to at least 20 Henrys) and capacitance (100 pf to 20 mfd) and be relatively accurate (especially with inductance measurements in the 100 milli-Henry to 20 Henry range).
                  In order to get this I don't think I'd need true RMS or ESR measurement capabilities.
                  The Extech 380193 seems to have exactly what I want (and a lot more) but it goes for about $200. Is there a meter I could buy in the $50 - $200 price range that will accurately measure capacitance and inductance to within 1% or less across the ranges I have mentioned?
                  Thanks.

                  Comment


                  • #10
                    Well Wolf, enter "inductance meter" into google, and start reading the results. See what is out there. I did, and instantly found:

                    Tenma LCR Meter | 72-8155 (728155) | Tenma
                    For $54. But you have to settle for 2-5% on large inductors. Good luck finding 1% meters on the 20Hy scale anyway.

                    Here's your Sinometer for $60, it has 3.5% on Hi-L scales.
                    Amazon.com: Sinometer 30-Range Digital Multimeter & LCR Meter, VC9808: Home Improvement

                    ANd $50 for this one:
                    Amazon.com: Mastech Digital Multimeter & LCR Meter, MS8222H: Home Improvement

                    Here is a project meter, and don;t forget to click on the "even better meter" link near the top.
                    Pretty Good LC Meter Project
                    Education is what you're left with after you have forgotten what you have learned.

                    Comment


                    • #11
                      Enzo
                      Heck, I used Google quite a bit to search for this and the problem was too many results.
                      Since I already had the Sinometer I wanted something a little better. Anything in its price range had an upper limit of 20 Henrys (not 30 not 25), which made me think these meters are probably churned out from the same factory.
                      When I searched for "inductance meter" it would produce results from $30 to $50, with a sudden jump to $200. So, I was wondering if there is anything above $50 that isn't just an advanced version of the Sinometer?

                      Comment


                      • #12
                        I'm using a Meterman 37XR which has true RMS, capacitance, inductance, and frequency counter. It has been replaced by Amprobe 37XR-A and goes for less than $150. Not sure if it will have the ranges or accuracy you want but worth checking into.
                        Originally posted by Enzo
                        I have a sign in my shop that says, "Never think up reasons not to check something."


                        Comment


                        • #13
                          g-one
                          I found the Amprobe version here
                          Amprobe 37XR-A True RMS Digital Multimeter With Component And Logic Test, 37XRA Amprobe - at the Test Equipment Depot
                          It costs about $127 and yes it doesn't have the "overkill" of a higher priced meter. (I really don't need inductance accuracy to .01%)
                          That seems pretty much what I was looking for and as I said it is not just an advanced Sinometer.
                          Good find.

                          Comment


                          • #14
                            Originally posted by jrfrond View Post
                            a lot of it collects dust and is just for wankin' e.g. the Huntron Tracker
                            I've never seen a Huntron Tracker that did anything but collect dust. I was given one that a local repair shop were throwing away, and couldn't find a use for it. The uni electronics workshop has a Huntron Tracker 2000, but I've never seen anyone actually use it.

                            I rarely need to measure ESR. In repair work, you can just jumper a known good cap across the suspect one, and if that makes it work, then the suspect one was bad.

                            When I do, I do it by hitting the cap with a square wave of current and looking at the voltage across it with a scope. The capacitance causes a ramp in voltage, but the ESR gives a little jump, and you can calculate it from the size of the jump, the test current, and Ohm's law.

                            A signal generator will do for small caps, but for big honking ones I'll hook the signal generator up to an audio power amp, so I have about 5 amps of square wave. I can measure down to milliohms of ESR this way.

                            You have to be careful about ground loops, because they also cause a jump that you can't distinguish from the ESR.

                            To measure inductance, I resonate the inductor with a known capacitor, and calculate the inductance from the measured resonant frequency. This gets you an estimate of Q while you're at it.

                            And the "ESR" of an inductor, you can measure to a good approximation with just a regular ohm meter. Doesn't work for "AC resistance" of pickups, though.
                            "Enzo, I see that you replied parasitic oscillations. Is that a hypothesis? Or is that your amazing metal band I should check out?"

                            Comment


                            • #15
                              The Huntron Tracker is just a fancy commrcial version of a little box techs have been making for decades. A little low voltage transformer - 6v is common - and a couple resistors. Set your scope to XY and connect the box. Now you can test parts on your boards. I never used one more than a couple minutes, but some guys really like them
                              Education is what you're left with after you have forgotten what you have learned.

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