Your Recommendation for a Reliable DVOM/DMM digital multimeter?

[Tul]

I'm using an Innova and an Equus DVOM. Each has 0.4 Ohms of resistance in the leads after cleaning. I'm wondering if that's normal and I should just continue to subtract 0.4 Ohms from measurements?

The other day, I was getting shotty mileage in my Toyota. I tested the fuel injectors and all were around 14.8 Ohms on car, engine cool (after accounting for the 0.4 Ohms), FSM specifying 13.4-14.2 Ohms and replacing out of spec. I did that, then retested them today off car and they were all 13.9 Ohms. I'm irritated, because changing the injectors was a chore.

Is there a more accurate DVOM that's not crazy expensive?

How do you clean the leads?

Thanks

 

[Andy22882]

I'm a mechanic for a living, so I don't know what is crazy expensive to you, since it seems like every scan tool, scope, DVOM worth having is expensive. But, the tool you're looking for is a Fluke. 87 series is pretty much the standard in automotive, the 88 was also good.

 

[Tul]

What's the difference between the 87 and 88?

Is used okay?

 

[Citation]

First, you can always buy a new set of leads. A decent set of gold plated leads will have far less resistance than the ones you are using. Do note that gold plating on the leads isn't very durable so it's best to save such leads only for when you really care about low impedance.

The Fluke 87 is really nice. I've had several and feel that, other than cost, it's about as nice as any meter I've ever used. My current "good" meter is a Fluke 187 which is the Fluke 87-4. It doesn't look like the classic 87 and apparently Fluke decided that was a mistake since they made the 87-5 look like the older 87s while changing the 87-4 into the 187.

BUT... the 87 is really expensive and for most people isn't worth nearly that kind of money.

In general I recommend Brymen OEM'ed meters. They are almost Fluke quality (and better in some ways) but sell for MUCH less. In the US the best ways to get a Bryment meter are the nicer Greenlee meters (DM-200A, DM820A and similar looking meters). The Amprobe AM-270 is also a Brymen. Finally, Matco sells a line of meters that, save for coloring, look identical to the DM-200A... all Brymens). On ebay you can often find these meters in very good condition for $50-100. Recently the Amprobe 270 was about $110 new on Amazon.

Another good used meter is the Fluke 27, it's an old military/mining model. About the size of a brick and probably stronger. They can sometimes be had off ebay for under $30. But you will need probes.

Others that might be worth a look are some Uni-T models and some Ideal models. You might check out some of the EEVblog youtube videos if you want to dive into meter comparisons.

As for leads, Pomona is really good. They make the leads for Fluke. Fluke leads (not "for Fluke" but actually "Fluke brand" are also very good and often cheaper than the Pomona's. The Brymen leads are also good though they will be sold under Greenlee or other brand names in the US.

 

[Citation]

What's the difference between the 87 and 88?

Is used okay?

The Fluke 88 is optimized for automotive work. I don't prefer it to the 87. The 88 isn't true RMS (but that generally isn't important for auto work). The 88 has a few features such as dwell and RPM measurements that can be calculated from measurements the 87 can take (duty cycle, frequency, etc).

Used Fluke meters can be a great value. I've owned over a dozen and all but one were used. However, you do risk getting a bad meter (done that) or a meter with blown fuses (at ~$10 each) or, worst case, a clear case of someone throwing parts together to suggest an older 87-1 is an 87-3 or 87-5. Not cool. If you don't know what you are looking at a deal might not be one in the end.

That said, used is a good option. Here are a few off ebay that look good to me (no affiliation with any sellers and no attempt to verify the meters are good)
https://www.ebay.com/itm/Matco-Tools-Basic-Multimeter-MD251-NIB/123883489217
https://www.ebay.com/itm/Greenlee-D...-Sealed-Smart-Meter-13-Functions/183844604338
https://www.ebay.com/itm/Greenlee-D...imeter-Case-Leads-Tested-Working/283493179350
https://www.ebay.com/itm/AMPROBE-AM-270-Digital-Multimeter-50-MOhms-1000V-10A/223581091771
This AM130 is all but the same as the AM270
https://www.ebay.com/itm/NEW-Amprob...Digital-Multimeter-PC-Connection/323892750232
https://www.ebay.com/itm/Amprobe-AM-91-TRU-RMS-Multi-Meter-Excellent-condition/193060291541
https://www.ebay.com/itm/Amprobe-AM-140-A-TRMS-Digital-Multimeter/383102635381

 

[Tul]

Thanks.

I need to measure down to 0.1 Ohms, at least for fuel injectors.

Greenlee's specs for the resistance is 600 Ohms to 60 MegaOhms, but does it go down to 1 Ohm?

So far, I like the Greenlee 210A for the lifetime warranty, auto ranging, and temperature sensing ability (have a bad catalytic converter).

I'm trying to read more about specs; what's the difference between the Greenlee 200 and 210A?

 

[mreisner]

25 years ago my Fluke seemed expensive. I have not needed to buy another one since. For the price of one decent dinner a year it now seems cheap.

 

[Citation]

Thanks.

So far, I like the Greenlee for the lifetime warranty, auto ranging, and temperature sensing ability (have a bad catalytic converter).

I'm trying to read more about specs; what's the difference between the Greenlee 200 and 210A?

The 210 can read thermocouples (temp sensors), the 200 can't.

 

[Tul]

The 210 can read thermocouples (temp sensors), the 200 can't.

Thanks. the Greenlee 210A's specs says it can read 50 Ohms. I need to read down to 1 Ohm for certain automotive functions and definitely in the 10 range for the fuel injectors. Can read down to 1 Ohm?

 

[MattT]

The other day, I was getting shotty mileage in my Toyota. I tested the fuel injectors and all were around 14.8 Ohms on car, engine cool (after accounting for the 0.4 Ohms), FSM specifying 13.4-14.2 Ohms and replacing out of spec. I did that, then retested them today off car and they were all 13.9 Ohms. I'm irritated, because changing the injectors was a chore.

Don't go blaming the DMM for that one. All the injectors ohming the same, and within 10% of factory spec, didn't justify firing the parts cannon. The injectors didn't all go bad "the other day".

 

[californiaHank]

Don't go blaming the DMM for that one. All the injectors ohming the same, and within 10% of factory spec, didn't justify firing the parts cannon. The injectors didn't all go bad "the other day".

+1
Don't worry so much about the actual resistance value you see on your display.
Only worry if one of the injectors shows a much different value than the others.
For a variety of reasons, it's real hard to get accurate, repeatable low resistance mesurements with a handheld dmm.

 

[Citation]

Thanks.

I need to measure down to 0.1 Ohms, at least for fuel injectors.

Greenlee's specs for the resistance is 600 Ohms to 60 MegaOhms, but does it go down to 1 Ohm?

So far, I like the Greenlee 210A for the lifetime warranty, auto ranging, and temperature sensing ability (have a bad catalytic converter).

I'm trying to read more about specs; what's the difference between the Greenlee 200 and 210A?

California Hank is correct about measuring low impedance with a hand held meter. For really precise low impedance measurements you need a 4 wire meter. But I also agree it's unlikely you would need such a meter to get your answer.

When the meter says it's minimum range is 50 ohms it means the full scale is 50ohms. The MD210 (remember the Matco meters I linked to are the same family of meters) is a 5000 count meter. Thus what ever range you are in is divided to 5000 steps. So if you are in the 5000ohm the smallest step is 1ohm and your accuracy will typically mean you can't trust those last few counts. When you are in the 500 ohm range the meter will read to .1 ohm.

 

[laser3kw]

I'm using an Innova and an Equus DVOM. Each has 0.4 Ohms of resistance in the leads after cleaning. I'm wondering if that's normal and I should just continue to subtract 0.4 Ohms from measurements?

The other day, I was getting shotty mileage in my Toyota. I tested the fuel injectors and all were around 14.8 Ohms on car, engine cool (after accounting for the 0.4 Ohms), FSM specifying 13.4-14.2 Ohms and replacing out of spec. I did that, then retested them today off car and they were all 13.9 Ohms. I'm irritated, because changing the injectors was a chore.

Is there a more accurate DVOM that's not crazy expensive?

How do you clean the leads?

Thanks

have you checked the battery in the DMM? if it is less than the 9v required, that may be affecting your reading. It should be replaced with only an alkaline type 9 volt.
When you checked them in car did you pull the connector and measure only the injector or did you stab the connector while it was attached to the injector?
Lastly, if I had poor gas mileage, I don't think I would go to the injectors right away, unless it is a known failure point for you specific vehicle.

 

[Davefr]

Don't rush out and replace your meter because you see .4 ohms with the leads shorted. I just tested my Fluke 87V and it reads .3 ohms with leads shorted.

That's the resistance of the leads. Most DMM's don't have the 4 wire Kelvin circuit.

You might cut that down by getting better gold plated leads.

 

[electroman187]

Don't rush out and replace your meter because you see .4 ohms with the leads shorted. I just tested my Fluke 87V and it reads .3 ohms with leads shorted.

That's the resistance of the leads. Most DMM's don't have the 4 wire Kelvin circuit.

You might cut that down by getting better gold plated leads.

Many meters have a delta or relative function which allows you to see a change from one measurement to the next. With your 87-V, you can short your leads together and press the REL button. It will zero your 0.3 ohms to 0.0 ohms. Then you will know the exact resistance of the measurement. You don't need to go buy thicker, gold-plated, low-resistance leads (but those things are good for other stuff).

Many meters have the REL function including the Greenlees that OP is considering. Yes, the DM-210A will read down to 0.1 ohms. It also comes with really nice gold-plated silicone leads.

 

[tool_scrounge]

Another good used meter is the Fluke 27, it's an old military/mining model. About the size of a brick and probably stronger. They can sometimes be had off ebay for under $30. But you will need probes.

+1 on this for the value play. The 27/FM version is true RMS also. The 8025b predecessor model is also pretty good. Hard to beat Fluke quality at discount used prices.

 

[Fedwrench]

Fluke 87 is probably the automotive standard on which other DVOMs are judged.

However, I've had great service from three brands over the years that won't break the bank.

First, is the model 597 from Electronic Specialties. It's rebadged by many tool trucks and can be had for about $100 if you shop around. ESI offers a wide range of DVOMs and accessories
http://www.esitest.com/597.html

Second option, Powerprobe DVOM is a great automotive meter that is value priced.
https://www.tooltopia.com/search.aspx?find=powerprobe+meter

Lastly, PDI. These meters have evolved over the years and are usually sold thru post secondary automotive school programs. I still have mine from school and it still works fine.
https://pdimeters.com/s_automotive.php

On a side note, a quality meter is an important tool for diagnosing and repairing late model cars but, what is more important than the meter itself, are the skills of the tech using it. If you don't understand how to use the meter and what it is telling you, you won't get far

 

[f121]

The other day, I was getting shotty mileage in my Toyota. I tested the fuel injectors and all were around 14.8 Ohms on car, engine cool (after accounting for the 0.4 Ohms), FSM specifying 13.4-14.2 Ohms and replacing out of spec. I did that, then retested them today off car and they were all 13.9 Ohms. I'm irritated, because changing the injectors was a chore.

Typical petrol injectors fail mechanically - they get bad spray pattern, go out of flow spec, so put in too much or too little fuel, leak a little bit constantly or don't open at all.

If they fail electrically, they usually go open circuit, a fraction of an ohm wouldn't make me assume an injector was bad. This may be different for direct injection petrols and diesels.

Bad gas mileage is often:
- bad temperature sensor (so the computer thinks it is on warm up enrichment).
- blocked cat (so the engine has to work harder)
- sticky brake (ditto)
- bad lambda(oxygen) sensor (so the computer thinks it's lean)
- boost leak on turbo engines
- heavy right foot

Buying a new multimeter is a good plan, I have a $100 fluke 115, it's excellent and worth every cent. It was a massive upgrade from my sears meter, but maybe I'll upgrade to a 88 when Ive got some spare cash.

 

[theoldwizard1]

What's the difference between the 87 and 88?

Is used okay?

87 is aimed at industrial use. 88 automotive,
I would stay away from used, unless it has a recent calibration sticker.

 

[theoldwizard1]

BUT... the Fluke 87 is really expensive and for most people isn't worth nearly that kind of money.

Concur ! Same for Fluke 88

In general I recommend Brymen OEM'ed meters. They are almost Fluke quality (and better in some ways) but sell for MUCH less.

Brymen 235 is a nice meter and only $125 on Amazon.

As for leads, Pomona is really good. They make the leads for Fluke.

I believe they are now owned by Fluke,

 

[electroman187]

87 is aimed at industrial use. 88 automotive,
I would stay away from used, unless it has a recent calibration sticker.

I wouldn't even flinch when buying a used Fluke, as long as there's no obvious signs of abuse. When meters get "calibrated", it's usually more of a confirmation of its accuracy. Even when adjustments are required, it's not often very much. If a meter reads 12.79 V when it's actually 12.82 V, is that going to change anything from a diagnostic point of view?

 

[theoldwizard1]

Thanks.

I need to measure down to 0.1 Ohms, at least for fuel injectors.

Measuring BELOW 1 ohm is very difficult and will require a very expensive meter.

You will need a "specialty" LCR meter like a Keysight (used to be HP when they made instrumentation) U1731C - Amazon $437.11 + $7.99 shipping. It has a 2Ω range is and a resolution of 0.0001Ω.

Even though this is handheld, it is meant to be used as a LABORATORY INSTRUMENT not a field instrument ! For continued accurate readings, it needs to be regularly calibrated against a "know standard" ($$$).

This is old, but still worth watching Digital Multimeter Buying Guide for Beginners

 

[theoldwizard1]

I wouldn't even flinch when buying a used Fluke, as long as there's no obvious signs of abuse. When meters get "calibrated", it's usually more of a confirmation of its accuracy.

Yes, but how else do you know if you are not buying a "pig-in-a-poke" ? (whatever that really means)

 

[CafeTools]

Just a Klein works fine.