3-meter test rig - multimeters?

Discussion in 'Armory - Q&A' started by Privateer, Feb 3, 2018.

  1. Privateer

    Privateer Podium

    Joined:
    Feb 8, 2009
    Messages:
    1,047
    Likes Received:
    131
    finally getting around to building a 3 meter test box. My plan is to keep the meters external and just build a box to connect everything.

    when I search for analog meters there's just a billion of them to sort through. any suggestions/links/brands&models to decent inexpensive meters?
     
  2. Fairfield_Fencing_Armory

    Fairfield_Fencing_Armory Made the Cut

    Joined:
    Mar 25, 2017
    Messages:
    30
    Likes Received:
    6
    They are hard to find but search the old threads for some links. Or you could build your own. You need small meters that can read in single ohms. Preferably with the 1 and 2 ohm readings really easy to see. Look at the scale carefully. I prefer analogue, but my Favero box is digital and it is amazing.
     
  3. Fairfield_Fencing_Armory

    Fairfield_Fencing_Armory Made the Cut

    Joined:
    Mar 25, 2017
    Messages:
    30
    Likes Received:
    6
    I looked through Amazon a bit...
    Tekpower TP8260L Analog Multimeter With Back Light, and Transistor Checking dock

    This one would work, but it would be better if the 5 was closer to the center of the scale to make the low ohms easier to read.

    Hand-held AC DC Voltmeter Ammeter Ohmmeter Analog Multimeter Voltage Current Resistance Measurement Tools

    This one looks small enough and the scale should be easy enough to read.

    Ideal Industries 61-610 Analog Multimeter, Pocket-Size

    This one would have been perfect. Notice the Rx1 and the 5 in the middle of the scale. Alas, it is out of stock.

    Hand-held AC DC Voltmeter Ammeter Ohmmeter Analog Multimeter Voltage Current Resistance Measurement Tools

    This one looks easy enough to read.
     
    Privateer likes this.
  4. neevel

    neevel Armorer

    Joined:
    Jan 17, 2000
    Messages:
    3,298
    Likes Received:
    286
    I have some of the Ideal meters- they were the closest thing to the discontinued Sperry SP-10 meters that used to be the go-to for test rigs. If they can be found elsewhere for a decent price, that's what I'd probably go with.
     
    Privateer likes this.
  5. dcchew

    dcchew Podium

    Joined:
    Jan 19, 2016
    Messages:
    612
    Likes Received:
    145
    My recommendation is the Gardner Bender (GB) GMT-318 that you can buy at Orchard Hardware Supply in California for about $25/ea. Now, the GMT-318 that is sold at Orchard Hardware has a Rx1 resistance setting with a 5 Ohm center scale. If you buy it online elsewhere, it may not have that Rx1 setting.

    The best part about this particular meter is that it doesn't seem to have much damping in the meter movement and is sensitive enough to catch most intermittent body cords. Another benefit is the small overall size.

    Andy, the GMT-318 is the meter I used in my body cord tester at the Anaheim NAC.

    If you're a hardcore advocate of old meters, the Simpson 362 low resistance meter is what you want. It has a 0-5 ohm low range scale and a 0-25 ohm high range scale. There's almost no dampening in the meter movement and is the ideal meter for testing lames. You can occasionally find them on eBay.

    By the way, I have a TekPowe TP8260L and it has too way too much dampening in the meter movement for me. It's also about twice the size of the GMT-318
     
    Last edited: Feb 3, 2018
    Privateer likes this.
  6. mfp

    mfp Podium

    Joined:
    May 10, 2002
    Messages:
    1,936
    Likes Received:
    273
    Currently available for $15.14 on Amazon with free 2-day shipping if you have Amazon Prime:

     
    Privateer likes this.
  7. brtech

    brtech Podium

    Joined:
    Nov 4, 2003
    Messages:
    2,330
    Likes Received:
    175
    One problem I have with external meters is that you can't detect shorts simply. That's a problem. I build shorts detectors into my 3 meter boxes using LEDs and some cleverness associated with the fact that if you series two 1.5 batteries by virtue of a short, you generate enough voltage to light an LED. You can use a switch and do it with multimeters, but you have to remember to use that switch on every cord test.

    I got the GMT-318 from Amazon the other day. Nice meter. One thing annoying about it is that it uses the smaller pin connectors for the test leads, not the normal banana jacks. Don't forget that with 5 ohm center scale, it's going to go through its AA cell fairly quickly. It has the zero adjust - use it frequently and keep an extra battery around.
     
  8. dcchew

    dcchew Podium

    Joined:
    Jan 19, 2016
    Messages:
    612
    Likes Received:
    145
    On my test box setup using the GMT-318 meters, I've converted the provided test lead probes to standard 4mm banana plugs. On my test box adapter, I've added 3 small push button switches that shorts the various body cord banana jacks. In the next generation of the box, I guess I could add 3 additional push button switches that would test A-C, A-B, and B-C shorts too.
     
  9. Privateer

    Privateer Podium

    Joined:
    Feb 8, 2009
    Messages:
    1,047
    Likes Received:
    131
    about the same price on HomeDepot, and I can have them deliver it to my local store for free.
     
  10. brtech

    brtech Podium

    Joined:
    Nov 4, 2003
    Messages:
    2,330
    Likes Received:
    175
    Did you modify the meter to change the jacks? It's easy to change the test leads to banana plugs. It looks harder to change the sockets in the meter to banana jacks.
     
  11. Purple Fencer

    Purple Fencer Podium

    Joined:
    Jan 19, 2001
    Messages:
    16,087
    Likes Received:
    544
    I don't know what meters are in my new box, but I'm putting it through it's paces and will post an eval in the near future.
     
  12. dcchew

    dcchew Podium

    Joined:
    Jan 19, 2016
    Messages:
    612
    Likes Received:
    145
    I changed the test leads from the standard probes to 4mm banana plugs. The connection to the meter itself are still 2mm pins. However, I did look into changing the meters, but it wasn't going to be a clean modification. Everything else I have (test box, patch cords, etc) are all standard 4mm banana plugs/jacks.
     
  13. brtech

    brtech Podium

    Joined:
    Nov 4, 2003
    Messages:
    2,330
    Likes Received:
    175
    I agree, looks tough to modify the meter itself. Curious how you use modified test leads on an unmodified meter :)
     
  14. St.Meow

    St.Meow Made the Cut

    Joined:
    May 22, 2015
    Messages:
    68
    Likes Received:
    6
    I bought a couple of these for use in a quick box I rigged for events while I design a nicer one.


    It's cheap, 20ohm center which isn't great but not impossible to see because the meter is pretty big. Takes a 9v and a couple AAs I think, not sure which it uses for it's 1x resistance mode. If you're doing armory with it and want it working in 1x mode, you will want to open it up and use a pair of small wirecutters to cut the leads on the buzzer. It is there for continuity tests, but if you're doing armory it'll be a pain to have the buzzer going off any time you have any cord plugged in, even if it is slightly too high (10ohms+).
     

Share This Page