The Measuring Machination

Equipment
1

This is the multimeter I’ve been using since 2018

It’s been working really well, and while I need something better when measuring nanoamps, it’s accurate enough for just about everything else I do.
If you really want the scoop on which multimeter is best, I recommend checking out the eevblog site and videos, but if you just need a reasonably good multimeter, this one seems fine to me.

3 Likes
2

I<3MyFluke87V but I’m biased. I know a bunch of guys w the Astro and if it holds up to shop use I won’t fault your choice. It’s solid and has great stuff.

3

Fluke87V is supposed to be very good, but is it 20 times better than the AtroAI 6000?
(It costs more than 20 times as much on Amazon right now.)

4

I have a Fluke 179 and an Amprobe AM-510. Amprobe is a good choice. It is not as expensive as Fluke but more robust than AstroAI. The Fluke 87V is over kill for most people.

5

Opinions vary, mine was via a program so I got a deal on it as well as the accessories they included so it all works alongside the PICO for diagnostic stuff. At the end of the day it’s whatever gets the job done under someone’s specific needs and budget IMHO.

6

I have the Klein MM400 off of that comparison. For what I use it for it’s been great, and I like that it came with the K-Type adapter, since I have other K-Type thermocouples kicking around.

Can’t go wrong with Fluke, but for the same cost (or less) as the Fluke 179 or 87V, I would rather get a Siglent SDM3045X, but 99% of the electronics work I do is on a bench so I don’t really need the portability.

7

I have SDM3055 on my desk. Pretty good, yet not as good as I would like it to be. Really the only complaint I have is that when measuring really small currents, the values will fluctuate when it switches between ranges.

8

That sounds about right, the more precision you want the higher the price bracket. We ran Siglent stuff in the lab I worked in, as well as some B&K stuff, and never had a problem with either brands. Admittedly we were using them for pretty coarse measurements. Anything precision we ran through DAQs, which were super sensitive and accurate, but cost multiple thousands.

9

I bought by Fluke 179 about 12 years ago, for about half of what it costs now. These things are crazy over priced now!

10

It’s ’Labor Day Weekend’ in the US and the whole world is on sale, so I thought I’d try a new multimeter. The persistent issue I have is I want a tool for measuring low resistances, under or around 1ohm. My resistor collection has turned into a bit of a mess and I’d like to get it sorted. It’s hard to tell if it’s my equipment, or a lack of technique on my part. I’ve seen some hacks and suggestions, but would appreciate comments or advice. Thoughts?

11

Here are a few options:

  1. The multimeter linked at the top measures with an accuracy of 0.1 ohms, not sure if that’s enough or not.
  2. The SDM3055 I have on my desk can measure resistance down to about a millohm, it can also do 4-wire measurements which helps with accuracy.
  3. Use two multimeters, hook up one in series with the resistor and set it to current measuring mode, hook up another in parallel and measure voltage. Supply a low voltage (less than one volt) to the resistor and calculate the resistance as V / I (I is current, V is voltage)
  4. Get a 10-ohm resistor, hook it up in series with the unknown resistor, run one volt through it. Measure the voltage over the unknown resistor. Then calculate the unknown resistor as: V * 10 / (1-V)

While #4 is a bit more complicated, the 10-ohm resistor limits the current which means you won’t accidentally burn anything.

Beware that measuring small resistances can be tricky, because the quality of the connection, and the resistance of the wires themselves may be larger than the resistance you’re trying to measure. (Which is when 4-wire measurements come in handy…)

12

The dream is one more decimal place, or .01 ohm accuracy.

That’s an idea! I do on occasion run into people with high spec gear, or a buddy will pick up something and want to share. The power supply I need may be the power of friendship.

Still don’t have a bench power supply to give me the right current. I could use one for sure and they seem to be more economical that some of the advanced multimeters, with multiple applications. This is a strong contender.

This is the pitch to the friend that lets me come hang out in their more advanced shop.

Thanks!

13

Reasonable power supplies can be had for fairly cheap, and is a good investment anyways. I should probably create a thread about power supplies, but I only have two of them, so there isn’t a lot of advice for me to offer.

14

My math might be off, but that’s more than I have. :grin:

Well, if you feel inclined to share what you’ve got so far, maybe some others will chime in. It’ll be like a Christmas catalogue :slight_smile: . Equipment threads are fun and very helpful. I bought new magnification gear after reading that thread. And here I learned that the sensitivity range I was looking for was outside of the typical affordable models AND that I could use math, a common resistor, and a power supply to solve it.

I suspect many of the people interested will have top tier gear, but it’s really knowing what to look for that’s key. Then I feel like I can choose wisely and get to a “good enough” set up.