Which Multi Meter to buy 2

[draymorris]

I am wanting to purchase a hand held multimeter(or meters)to use in an injection molding facility. Our machines and facility use every type of electrical and electronic circuit it seems, our machines have analog, digital and the normal AC votage ciruits in them, a few have frequency drives in them as well, and there have been times when we need to measure very accurate DC Voltage that our standard multi meter would not do the job. We have also had the need to measure AC Amperage upto 400 A as well as DC mA very accurately. I am just looking for suggestions since I am not as educated as well as I would like to be. My goal - when the service tech on the phone says "tell me what ????? measures" I can say "OK" instead of "I don't have an instrument that measures that"

 

[buzzp]

Typical meters are not as accurate at low current or voltage levels as they are at higher levels. Say a meter measures up to 600VAC. The accuracy at less than 5V say is worse than at 600V. For current measurements, it might make more sense to have a seperate meter. Clamp-on preferred since the circuit will not have to be broke to measure current. Also, make sure all your meters are advertised as true RMS devices. This will make a huge difference when it comes to measuring something out of the drive. I would say your looking at three meters; one general meter(DMM-digital multi meter) that can measure a lot of different signals voltage and current, another volt meter for low level measurements, and a clamp-on meter (may need two of these too). Review a data sheet and see if the accuracy at low levels is acceptable like a fluke 87. If you calibrating equipment, I would suggest a desk top meter like an HP, hewlett packard (changed names?). Hope this helps.

 

[pablo02]

If you have a regular electrical supplier, they may be a supplier of various multi-meters -- visit with them, they may be able to provide demos for you to review and try out -- don't go cheap, buy a reputable meter from a dealer you know...

Fluke is a good mfg. there are also several others. You may even find that you need to purchase several different models for different applications: a stand type (e.g. Fluke 87), a clamp-on type, or even some of the newer scope-type meters or ones with analog outputs, etc.

see

http://www.fluke.com/us.asp

 

[dgallagher]

Here is a link to our popular multimeter that also includes infrared temperature measurements:

http://www.reliabilitydirect.com/multimeters/EXT-400.htm

For a variety of other multimeters, you may look at:

http://www.reliabilitydirect.com/multimeters/multimeterindex.htm

Have a safe and happy holiday season.

 

[draymorris]

Thanks for the input. It was all very helpful. Is Extech a good brand?

 

[ScottyUK]

Hi draymorris,

HP's instrument division split off and was renamed Agilent Technologies.

Keithley Instruments make some fine bench instruments which will meet your more demanding accuracy requirements. The Model 2000 meter is as accurate as you could reasonably need outside of a standards lab.

Fluke make a number of hand-held process calibrators which are very good at the DC mA level, but don't have a very extended range.

I think you should consider a good general-purpose meter such as one of the Fluke 80 series, and invest a bit more in a decent bench instrument for the demanding jobs when you need the accuracy.

The high current measurements can be accomplished with high accuracy using a Rogowski coil based probe. LEM-HEME market one in Europe. They are limited to AC only, but have excellent bandwidth and phase response.

It is worth considering purchasing a second-user bench instrument. In the UK, there are a number of dealers who bulk-buy instruments from government facilities, and sell on at a fraction of the list price. It is possible to pick up some real bargains.

 

[busbar]

If the equipment will be used at line voltages, an important consideration is the meter’s installation/overvoltage category, referenced in UL Standard 61010B-1

 

[jbartos]

Suggestion: Beside a hand-held multimeter that should measure true rms to account for the harmonic content in waveforms, it is recommended that a power quality analyzer is not ruled out. AC amperage up to 400A in your facility and a type of loads can justify it.

 

[GordS]

Remember to investigate safety considerations in your selection. What sort of overvoltage and overcurrent protection is available within the meter? Can it withstand the expected environmental extremes - such as temperature and humidity? How durable is the instrument? As an example, an instrument built as per UL1244 can withstand 6000 operations of the rotary selector without failure (there has been an incident wherein a multimeter created a phase-phse short through the metal deposits on the printed ciruit board).

So check the specs and get the best. You don't want to be holding an instrument at the time it fails.

 

[PUMPDESIGNER]

Just one little practical piece of information.
I know purists will jump on it perhaps,
But if outright durability and close to indestructability are desired you can use the Fluke 27.
It was designed for the Armed Forces. It is water proof and can be dropped into a bucket of water, it has full "O" ring sealing.
I have two, each is over 15 years old.
They get wet frequently because they are carried around and go into water spray areas.
Have burnt the leads off them too many times to remember.
They are almost indesctructable.

Fluke 27s are not rms, some think that fatal, we do not. In the vast number of repair and diagnostic situations they are most appropriate. If better is required we go get the Fluke 87.

If you really want to live nice, throw away the lead sets that come with the units and buy the best lead set you can afford with all the clips and jaws, and all the other nice stuff to make work safer and easier.

PUMPDESIGNER

 

[GusD]

hello draymorris

Great endorsement for "Fluke" equipment.It is true ,Fluke
makes very reliable equipment,but so do a lot of other
manufacturers.HIOKI,HEMI,HP and probably a lot of others.
As for the meter test "Drop in the water bucket".I would be very concerned about using a meter that was dropped in a bucket unless one is measuring 6 or 12 volts.Any test on systems >65 volts could have disastrous consequences.
The seal don't last forever.

GusD

 

[buzzp]

I can see arguments on an averaging type meter (not rms) not being effective. Depends on what type of troubleshooting your going to do. If you simply need to know power is there, then it will suffice. If you need to know if the power is within a specified limit like +-5% then I would definately use an rms meter. If there is no distortion one day, it does not mean there will not be the next (again depends on application and location).

 

[jbartos]

Suggestion: Also, it depends on nature of measurements. E.g. if steady state values are sought, and small variations in time are present, then the discussed and recommended meters above will suffice. However, any spikes, fast transients, wave distortions, etc. need an oscilloscope or similar device, e.g. power supply quality analysis device.

 

[afterhrs]

Dray, here is my suggestion.
For the DC milliamp measurements, I would use the
Fluke 179 hooked up in series with the circuit.
As for any amperage measurement over 1 amp AC or DC, the Amprobe AC/DC 610 works great.

I use this combination on a daily basis and find it works
quite well and is a portable set up.
What ever you decide, PABLO 02 is absolutely correct,
You get what you pay for!

Regards,
Afterhrs