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What multimeter should I get? Answered

After making my first few electronics projects I've learned that I really should get I multimeter so I don't screw everything up. So I've been looking around a bit and there's a lot of choices out there and I don't really know what features I should be looking for except I do know I want to get one that can read loads up to 4 to 5 amps (or maybe even more). I only want to spend around $30-$60. I found this one on amazon http://www.amazon.com/exec/obidos/tg/detail/-/B000JQ4O2U/ref=ord_cart_shr?_encoding=UTF8&m=AMH4W1K8OCGMX&v=glance does this look like a good one?



9 years ago

I would recommend two cheap meters over one better meter. That way you can measure current and voltage at the same time (for example.) I have several of those cheap HF meters, and they work for almost everything I normally do. After you've spent the whopping $10 on the two cheap meters (less if you wait for a sale) and use them for a while, you'll get a better idea of what features you'd like to have in a more expensive meter.

I agree that an analog meter has some advantages, but it's been a while since I've actually used mine. (although, I have a "lab" power supply with analog current/voltage meters, which is very handy for the most common setups.)

I saw in the product description that this unit has auto/manual ranging, what does that mean? I also saw this: "AC/DC 1000V/10A 200KHz 200uF 40Mohm Relative Measurement hFE Diode Check Continuity" under the technical data, does that mean if you connect it to anything above 1000v or 10A that you will fry the unit or it just can't read it that high?

It'll fry the unit in most circumstances. Spikes in excess of 1KV are almost guaranteed when testing HV transformers and other inductive devices (yep, I've ruined a meter or two.) Whether or not the meter survives depends on the meter construction and the duration of the spike...

There are some ways to limit the danger: for instance, if the meter has an on/off switch as well as a range selector, don't turn the meter on until after the inductor is switched on.

View meter info here (they warn against exceeding input specs.)

What analog multimeters would you recommend for high voltage/ high amps?

My Sears MM has survived 20 years, but a quick check show that Sears only offers one analog model, and it's not very impressive. Since DMMs are so cheap, it might be difficult to find a decent affordable one. Nacho's right--a good DMM will work fine unless you're planning on mostly high voltage and current usage.

I notice some new analog models have FET input buffers (so they'll have high-impedance input like DMMs), but they wouldn't be any more robust around spikes than a digital model.

The old-school analog meters can still be damaged and fried, of course, but I've had my meter slam off the scale and it still lives. When that happens you withdraw the probe very quickly--but that wouldn't be quick enough to protect SS components.

When a DMM tracks the input values, there's usually a time lag between readings. So you keep the probe in contact longer, when an analog meter would be obviously over limit (which is how I fried my last DMM--watching several confusing readings, which were the death-throes of the meter.)

Also, the inertia of analog meter movements helps to prevent in-rush damage--they can't physically respond quick enough to damage the meter. Like any inductive device they still have voltage and current limits, of course.

  • auto/manual ranging - you can either select the range you want to use or the unit will do it for you. Auto-ranging can cause problems if you are not careful and read 1kV as 1V. When working with low voltage, this is not a big deal, but can be painful when dealing with higher voltage.
  • AC/DC - swings both ways heehee
  • 1000V/10A - rated limits. You can usually go a little above this, but the readings are likely to be less accurate when you get near the limit. You will damage the unit (or blow a fuse) if you go much above these figures.
  • 200KHz - unit is rated to give reasonably accurate AC reading up to this freq. Going above won't harm the unit, but the readings will be less accurate. Unit is probably designed to be most accurate at 50-60Hz, but claims to be accurate up to 200K.
  • 200uF 40Mohm - the load the unit presents to the circuit being measured. Using the meter is just like inserting a 40Meg resistor and 200uF capacitor across the measurement points. Should work for all but the most sensitive circuits. If you needed something with better specs, you'd know it. ;)
  • Relative Measurement hFE - I have no idea. FWIW, Wikipedia says "hFE stands for the small signal Forward Current Gain of a bipolar junction transistor." I'm guessing it's some kind of transistor check.
  • Diode Check - has a diode check function that uses lower voltage/current than the ohmeter.
  • Continuity - has a very-low-resistance indicator. Possibly an LED or beeper, or both, that activates when you are measuring the resistance of a short. Handy for checking fuses without having to look at the meter. Check the manual to see if it can be used to find the polarity of diodes.
> fry the unit or it just can't read it that high?
. Most meters can handle a little outside their rated range before they are harmed. Accuracy will degrade, but is not a serious problem with most modern DMMs, especially for a DIYer, unless the ADC hits it's limit. Do you really need to know if it's 995V, or 1005V, or just pretty-close-to-a-thousand?
. I didn't see any accuracy ratings for the unit you linked to, but unit should work great for all but the most extreme DIYers (assuming it's of decent design and manufacture). For most DIYers, ±10% is more than accurate enough, as long as it's repeatable.
. ROFL. I just checked and on their $20 model, the worst spec is ±1.90%. If the meter is put together reasonably well, it should be a great addition to your toolkit. Matter of fact, if you don't need auto-ranging, the DT9205 is a much better value. It even comes with a holster (very useful if you use your meter in the field).

. I'm not familiar with that brand, but it looks like it has all the features a DIYer needs. I prefer the Fluke brand - very reliable, accurate, and rugged, but they tend to be pricey. My all-time favorite, the 77, has been discontinued. :(

For a first multimeter, I wouldn't recommend spending even $10. Go to a place like Harbor Freight, and pick up a cheap one for $4, or $2 if you wait for a sale. Better yet, pick up a few...they're practically disposable. They won't last you thirty years like a good Fluke will, but they are surprisingly capable for the price, and will last plenty long enough. Once you're more familiar with it and know what exactly you want, you can upgrade to a fancier one.

I note from your profile that you are in KCMO... You can order online, but there are stores in Independence and Shawnee (and other places, but those are closest).

i guess its ok i have a really cheap one (like 15 $ equivalent) and it is acceptable - sometimes hs a glitch that requires you to switch off and on to fix but does not happen much


9 years ago

My personal preference is to have two meters--a decent solid-state meter where high-impedance meter input is needed, and a medium-sized analog meter for HV and high current testing. Having fried a SS meter or two in my day, I testify that the analog meters are much less susceptible to spikes and over-voltage.