Digital Multimeter Portable

That brings back memories. I don't have the answers, but I'm sure someone does.

It's one thing to learn about this issue and fry a couple of cheap meters as a teenager living at home. It's quite another be destroying expensive company test equipment.

I'll be interested to hear the replies. I'd also like to know about low end meters that have this type of protection? What is is called in a spec sheet?

In the meantime, I'd have no problem giving the newest employees cheaper piece of gear for 90 days. When I see a piece of kit for a ridiculously low price, sometimes I'll pick it up as an amusement. As a result I have a few meters that I've been using for years that I've picked up for as low as $2.99 in both analog and digital. Amp's too! I guess that most of my best equipment must have died from overuse? (do not hand out 2.99 metres)

--- It's really the only caution that I've given anyone using a meter for the first time.

..Not to connect voltage to the meter when it's set to read resistance or it will fry.

I would have thought that this problem was overcome.

I know there is a very good reason it exists

The quality of the technician is directly proportional to the amount of equipment he destroyed in A school. Unknown Air Force Chief Master Sargeant.

That being said there are a couple of schools of thought.

A) A technician for NASA opened the wrong valve on some rocket, flooding the area with fuel. No one was hurt and it didn't ignite, there was talk of firing him and other punitive measures. One of the senior engineers remarked, "let it go, he'll never make that mistake again."

B) All technicians must provide their own tools.

C) Having been on both sides of this issue, sometimes you just have to sit back, have a couple of cold ones and move on.

In our Veterans Administration hospitals, Doctors and their supervisors manipulated admission schedules, for monetary gain. Several patients died because of the delays, as of today, no one has been sent to prison, required to re-imburse the system, been fired or even reprimanded.

Did anyone die because of this? Was it malfeasance, negligence or did some one energize a properly tagged out circuit?

I am truly impressed by the fact that you asked for advice, as opposed to grabbing the nearest heavy object and beating the living snot out of him/or her

I've got a Mastech digital multimeter and I have never had issues with it from accidentally hitting a live line while doing resistance measurements.

To be honest I have never had any of my other meters (too many names to list!) act up from doing that either. Even my free ones from Harbor Freight.

SOunds like the one you have is a crappy design. Is it a newer fluke sub brand?

I was hoping to hear the problem didn't exist, but I'm not convinced enough to go try it out.

My Fluke 87-III has survived line voltage measurements when on the resistance scale. Didn't even blow a fuse, but I sure got a strange resistance reading. I can't say the same when measuring a voltage on the ampere reading scale. For that, I was honored to have purchased a very expensive 44/100 fuse ($16). Haven't made that mistake again since.

I have done that too! But it is a great feeling to realise that expensive fuse did its job and cost a lot less than a new meter and medical repairs to self (if possible). Certainly an area of great safety improvement in testgear and a part of the meter spec the original Post should include.

Are you sure you didn't just blow the fuse?

On a point of information, does the fuse protect anything when you apply volts to the resistance measurement position? I thought it was high volts rather than high current which killed the circuitry in this context.

Any multimeter I ever had, had fuses for just this reason...I have blown enough to know(in my younger days of course)....If you are checking continuity on a circuit which turns out to be energized, the needle will peg and vibrate, this is a sign that every technician knows...you have a few seconds to respond, which usually takes about <2 seconds to remove one of the leads....any longer than a few seconds and you better have a replacement fuse, or at least some tin foil...or it's the backup meter....

The fuses in a multimeter do the same thing they do in any circuit. They protect from over current which only happens in the amperage measurement modes.

In all other modes the fuses serve no purpose and offer zero protection from overvoltage.

From the KYORITSU 1009 operating manual:

http://www.kew-ltd.co.jp/en/download/pdf/manual/english/1009_IM_92-1548E_E_L.pdf

It looks like only current is protected by fuse. The ohmmeter function likely died from voltage abuse.

Fused test leads are available for every make of meter there is. Get some...

nice reading.

even though my use for it would be questionable.. I look forward to the day I outfit my workbench with adjustable ac/dcp ower supplies, meters, waveform generators and an dbbl ospope.

Then I could get rid of at least one file cabinet full of power supplies etc. ..as if I'd get rid of a file cabinet full of power supplies..

I've got one of these:

Now, if I cold just figure out what all those squiggly lines and funny symbols are I'd be ready to be a full-up sparky.

I have one too - when you figure it out please tell me!

As long as they keep making better, and better idiots it'll be difficult to make idiot proof multi-meters.

Most auto ranging meters have overload protection for just that eventuality, and according to the instruction manual for the meter in question yours has said protection on the resistance scale up to 250V RMS for 10 seconds (see page 16).

Realistically, 10 seconds is a long enough time to become aware of a problem, if your technicians can't figure out that they have connected the meter incorrectly within that safety window, then perhaps you should send them back to school.

If the circuit has a voltage higher than 250V RMS (350V peak), then damage can occur much faster than the 10 seconds, but again, your technicians should be smart enough - and keen enough to survive - to ensure that the circuit is disconnected when working with voltages anywhere near that level.

...and the reason <...local distributor/traders...> are not being contacted directly on this topic is what, please?

One of the key things in becoming a skilled tradesman is learning to do the "little things" the right way as a matter of habit. Back (in the stone age) when I learned to use a multimeter, I was taught to always leave the meter in the highest voltage range when I put it down. That way I always remember to check if a circuit was "hot" before I tried to measure resistance or continuity, or try to measure current across a load

I looked up the Model 1009 spec sheet.

It claims CAT III 300V.

Even my cheap 3 1/2 digit meter has CAT III 600V. I believe CAT III covers surge levels likely at the incoming point of a building.

This suggests that though your meter has more digits and "bells & whistles" it is not as robust as less capable meters.

The 1009 claims 250V rms survival on ohms range, which seems typical of modern meters.

Of course, if typical supplies for "machines" in your application exceed 250V, it may be unreasonable to expect protection on ohms ranges.

What voltages were applied "in error" by your users??