DMM Like the Fluke 112

Only cheaper...of course I'm casting about for opinions & facts regarding a good value in a small DMM. Important features for this meter are (back) lighted display, 10A (20 peak) current range, larger readout desired, anything else is a +.

If something else comes close to a Fluke 112, is well made and, thereby, safe on <600v, for less $$, I'd appreciate your input. Otherwise, I may just get another 112.

I have had a LOT of DMMs both personal and for my company and none come near the Flukes

When I was shopping around for a good DMM most recommended a Fluke, so I went with the 112 and couldn't be happier! Previously, I had cheap meters and this 112 was the best I have ever seen, the quality is something else. I just wish I had more knowledge about electronics so I could get the full benefit of this meter.
When a product is recommended by several on this forum you can bet it is a good one imo!!

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I'm not sure how the 112 compares... but I've got the 189. Great meter, tons of capability, excellent DC accuracy. Cost a F***ing pile though!

jayflash said:

Only cheaper...of course I'm casting about for opinions & facts regarding a good value in a small DMM. Important features for this meter are (back) lighted display, 10A (20 peak) current range, larger readout desired, anything else is a +.

If something else comes close to a Fluke 112, is well made and, thereby, safe on <600v, for less $$, I'd appreciate your input. Otherwise, I may just get another 112.

Click to expand...

You're paying a great deal for safety features on Fluke. There are two fuses inside a Fluke and each of these fuses cost more than a cheap DMM. Both fuses (0.44A & 11A) are rated 1000v and 10,000A+ interruption current, which relates to the ampere capability of the power source.

One thing a 10A (1000A IR) and 10A (170,000A) fuses have in common is that if you accidentally short the ammeter across a car battery, they will both blow and cost you money for a replacement fuse.

But, let's say a tech accidentally try to measure the voltage across two phases on the secondary of a 5,000kVA 480v transformer while the meter leads are in ammeter ports. The proper IR and voltage rated fuse will blow and contain the force w/ in the fuse.

The 10A 1000A(IR) 250V fuse won't be able to stop the current, which could mean the meter explodes violentlycausing an arcover between busbars, which then creates a massive blast and continue to melt things down until the utility company's protection equipment on the 12kV side of the transformer shuts it off.

I'm talking about working on something like this:



So.. since current measurements I make are mainly low voltage DC and the short circuit current of the source is not that high, I dedicate a cheapie for current measurement.

Comparing the readings in voltage mode, the accuracy is decent. I like my Flukes (I have three), but I admit the cheapie is just fine for many uses.




That CEN-TECH cheapie was like $5.00 at Harbor Freight
http://www.harborfreight.com/cpi/ctaf/displayitem.taf?Itemnumber=90899

If you want backlight, they have another cheapie w/ backlight
http://www.harborfreight.com/cpi/ctaf/Displayitem.taf?itemnumber=92020

I recommend you buy two to prevent wear and tear on the rotary switch. Leave one permanently dedicated to "10A" and the other one to 2,000mV or 2V and juggle between the meters, not "modes".

Since you already have a Fluke 112, you can open the cheapie and calibrate it to 112 using the only potentiometer inside. Just apply a 1.5v battery in 2000mV range and adjust until the display matches the Fluke. It might not even be necessary if yours is close enough.

Thanks for the HF link, Ha Ha. For this particular project the accuracy of the HF should be good as is. I've found most cheap DMMs surprisingly accurate compared to the old mechanical movements on expensive (Simpson 260) VOMs. Since the 112 is used on the 480v equipment at work I don't need the interrupting rating at home. At worst the meter will turn into a glob of plastic when I forget to return the + probe to the proper jack when applying 120v to it.

Maybe I should get four - for insurance!

Hey Handlo....you've got me thinking about the switch wear....I have the Fluke 112 and was just wondering how many times you could turn the switch on before problems arise? I turn mine on an average of 2/3 times a day. Thanks!

lrp said:

Hey Handlo....you've got me thinking about the switch wear....I have the Fluke 112 and was just wondering how many times you could turn the switch on before problems arise? I turn mine on an average of 2/3 times a day. Thanks!

Click to expand...

I have no idea, but it should last a whole lot longer than the Cen-Tech. The Cen-Tech is built such that circuit board itself is the shaft support and you can see worn down powder of yellow plastic when you take it apart.

You can save a whole lot of wear on the jack and dial if you have another meter dedicated for measuring current.

Handlobraesing makes a very good point about dedicating a meter for current & one for voltage - it's efficient and prevents mistakes.

I wouldn't worry about the 112's switch - rotate to your heart's content!

Thanks guys!!

HandLo:

What's your point here? No meter is going to prevent you from putting yourself in harms way!