Guys, I have two multimeters, one Fluke, one Greenlee and both are reading way off. I have looked for someplace to recalibrate these items, but can’t find anybody! Does any know where I can send these meters? And how much does it cost? Thanks in advance. Bones
We use Transcat at work, great service and usually pretty quick. Not sure what meters you are using or what is wrong but repairs/cals go from cheap to you probably should just buy a new meter.
Oddly enough both meters have the same problem and caused me a lot of problems! They both read way low on A/C voltage. But DC voltage it apparently right on! I don’t have access to them right now for pics, but both are medium meters with volts, ohms, amps. I think they sell for about $200 new. Thanks, I will check Transcat out. Bones
Have you tried a new battery? Sounds dumb but I've been around for guys to get hurt because their battery was low. We now require all new meters to have a battery life monitor...
For what it's worth, even some Fluke's aren't calibrate-able. I worked in a Cal lab briefly doing mostly multimeters, micrometers/calipers and pressure gauges. A common thread for things that can't be calibrated is if the error isn't linear, meaning the same amount of error across it's measuring range. We would work about 50 Flukes per week and had about a 5-10% failure rate depending on models. Bear in mind that these were used and abused...
Have you tried different sources for your AC readings? How off were your readings? You would be surprised how much of a difference you will see at different locations/homes/businesses etc. Two meters reading the same tells me there might be other problems.
Well , the Fluke, goofed me up about two years ago, so I shelved it. We lost power at my house a while back so I fired up my Bobcat welder to run the house. I was double checking everything with my Greenlee meter and it read about 80 volts A/C. I checked the battery on the Bobcat, 13.7, perfect! This was exactly the same thing that happen to me with my Fluke, two years and 80 miles apart! Only crap like this happens to me! Lol These are not cheap meters, supposed be some of the best! I had to go to the back of my tool box and get an older cheap multimeter that I bought 40 years ago to check my stuff, now. . But before that I used a 1920s volt meter that I had in my stash to verify my voltage! Bones
I see the volt measuring selection is marked both ac/dc. How is the selection made? Manually with the buttons above? Or auto? My fluke has independant selection for valts ac or volts dc.
Was the AC side of the meter reading (RMS) Root Mean SquareVoltage rather than peak? 120V AC peak is about 85 V RMS. House current is normally RMS coming out of the wall, but with the generator, anything is possible. Stick the meter in a good wall outlet, and see what it reads. Should be right around 120V RMS
As stated above. If the generator was involved with both of your meters than that could be the source of the low readings. I’m not an electrician but did work on the distribution side. Depending on what type of service you have 120/240 or 110/208 is ideal. Low and even high readings can be the result of bad connections, broken/corroded neutral and faulty high tension transformer. As stated, check your meters again at a known good source.
I'd go buy something at Harbor Freight and use one of the coupons for a free multi-meter. Then I would use it to check the same A/C source that you are using the other meters on. I know its HF, but if all 3 meters read about the same, then I don't think the meters are the problem. Its extremely rare for two quality meters to both have the same problem.....especially when they are completely different brands. Or see if one of your friends has one you can borrow.
It selects automatic, between A/C and D/C. ( I think) . Frozenmerc, I do not know what RMS is, so I don’t know if it was reading it! Lol. I’m a simple guy, if I select voltage, I expect it to read voltage! Maybe that’s why I get along with cheap meters! I did have a friend at my house during this time amp didn’t his meter along with my old 1920 volt meter read the right voltage. 120 A/C and about 220 when measuring between the two hots on 220.( I was using his meter for this reading). One odd thing about my meter was when reading volts from one leg to ground I would get about 80 volts, when measuring between the two “ hots” it would read 40 volts! This was with the Greenlee. PS: my old meter was an analog, the Greenlee and Fluke are digital. Bones ,
I would guess that your two digitals are being influenced by the noisy power quality of your generator. Calibration is not likely to fix that, it is a “digital voltmeter thing”.
Something I didn't understand for a long time was the "neutral" wire. In the electric panel there is a place for "ground" and a place for "neutral". My understanding now is that the ground is for a "local" ground at the site of the panel which is established by a stake driven into the earth and connected to the panel. The "neutral" is a ground that is from the electric company source. Thats my understanding.......correct or not. Anyway I'm wondering if whatever you are grounding the multimeter to, might not be a good ground......ergo the bad readings. Also, I didn't think you were supposed to take a reading between two "hot" leads. Again, I admit to being an electrically challenged individual and have no idea why I'm trying to give advice on the subject.
I am not an electrician either and I know there is a ground and a neutral! But the go to the same place on the circuit breaker panel. To me, that makes the about the same thing. I’m sure an electrian would disagree! If you test between the two “ hots” you should get twice the voltage of one “ hot” to ground/ neutral. This is my understanding. Bones
Ok with more information I will agree with @FrozenMerc and @wraymen on the RMS, if both instances involve your generator, the issue likely has to due with the waveform of the voltage being created by the generator and how your DMM clips the peaks. Typical DMM average out the signal, so any voltage profile that is not a perfect sine wave will result it a reading that is from -40% to + 10% of the true value
When I was using my Fluke meter a few years ago it was at a camp site with regular line power. It is digital , but unlike my Greenlee it has a manual switch for A/C and D/C Voltage. I quit using it after that. I just put it up on the shelf. Then two years later my Greenlee did the same thing. It could be me, but I’ve never had any problems reading multimeters before. When my Fluke went bad, I had the electrician check with my meter against his, he said it was way off! Bones
I guess that’s the problem with modern technology! Back in my day when you put a gauge on something it told you what it was! That’s kinda the purpose of a gauge. Today you put a digital gauge on something, it may read right or not! Kinda defeats the purpose of a gauge, in my books! I’ve got a couple of old analog meters in the back, I think I’ll start using them. I’ll use the two digital multimeters for scotch blocks. lol Bones
We use the saying "trust but verify", so test your meter on a known value, before measuring an unknown, if your unknown measures something unexpected, stop and verify, that could be with another meter or with a drawing, etc. The old analog meters still have their place, especially on noisy circuits. Do you have another known ac voltage source to check either DMM?
I could go out and check it again, but I can’t today! I did try to check it against a known voltage, but the problem at the time was I didn’t have a known voltage. So I checked it on my 12 volt battery and it checked perfect. I know that’s A/Cand D/C but it was all I had. I then dug out that 1920s analog volt meter and both legs checked fine. I could not check between them, as the old voltmeter only went to 150 volts. Bones
My Fluke has a separate setting for AC volt and DC volt. It does not automatically sense and switch. This may be your problem. Sometimes, I check my Alternator for AC current, which would indicate that a diode is leaking. It is possible to have both DC and AC current on a circuit, I believe that is the reason you have to "tell" the meter what you want to read. Post a close up picture of the face of that Fluke. That Greenlee has a "Select" button on it. I'll bet that you have to select AC (~) or DC (-) after you have rotated the dial to V. Probably similar deal on your Fluke.
I bought a generator out of an old motor home on the condition it ran and worked Took it home, got it running and checked voltage with an old Fluke 75 DMM. Stayed pretty consistent around 120 volts. My Fluke T5-600 also reads AC/DC voltage on the same setting
My Fluke is not reachable for me right now, but it does have a manual switch for A/C vs D/C. I did not get a manual with either meter. Maybe some one here has a manual for the Greenlee? Bones
That is not correct.... Grounds and neutrals are supposed to be identical electrically speaking, i.e. there should be NO difference of potential between them. But they serve two completely different purposes. They are 'bonded' together at the main point of service to furnish a 'solid' zero voltage reference point to ground through your ground electrodes and you can connect both neutrals and grounds to the same buss bar, but once they leave the main panel they must be kept separate. So while they're electrically identical, once they leave the panel they do two different things. The difference is a neutral is a current-carrying conductor, a ground isn't. The neutral is there to complete any 120V circuit (120 to 'ground') only, the ground is an emergency path to ground that is only used if there's a failure in the internal grounding of whatever device is connected to it. If you've ever gotten even mildly zapped using a metal-cased tool on damp ground using a cord missing it's ground plug, that's why. A ground should NEVER be used in place of a neutral to complete a 120V circuit. Most electrical items these days are double-insulated (making them 'intrinsically safe') so they don't have a ground connection. Grounding is the most misunderstood part of electrical, not even the engineers fully understand it. During my career I saw some grounding means go from being required to illegal and back again. There's still certain exceptions depending on circumstances and when the NEC updates the code it's guaranteed you'll find changes in the grounding section every time as they find another weird thing they have to deal with. Bones, your meters have failed. It will probably cost more than their worth to repair... if you can even get them repaired.
Absolutely, that is the principle on how audio and instrument amplifiers work. All through the amp there is both AC & DC current on the circuits, DC is what powers the amp, the audio signal is AC, both run on the same wires, capacitors are used to block the DC where it's not wanted (capacitors will pass an AC signal, but will block DC).
Thanks for chiming in! While I’m not an electrician, I have done a lot of wiring, both A/C and D/C. Thanks for explanating the neutral VS ground. I knew the neutral went back to complete the circuit and the ground went to the ground and that they came from the same buss bar, and I knew the grounds most important job was safety. I had never had anybody tell me the difference in words! I kinda wire A/C like a parrot. I’m kinda glad you told me my meters have failed, that way the meters are wrong and I’m right! Yea! But now I have two pieces of expensive junk ! I just can’t win! Lol Bones
I've lost track of the meters I've replaced over the years. But generally unless the meter is in the $400 and up range it's just not economically feasible to fix 'em... I could tell multiple weird grounding stories. The one that drove a bunch of people crazy was a brand-new campground shower building on a AF base that was zapping people taking showers. They'd start their shower, no problem, it was when they went to turn the water off they got nailed. Womens shower to boot, they were not happy at all... LOL. They were getting zapped off the metal shower drain grill (we think), which had NO connection to anything metal (all the drain piping was plastic). We double and triple-checked the grounding/bonding at the building, turned out the base installed a 2300V transformer for the service and failed to connect the base HV 'neutral' to it, using just a ground rod. They had crappy soil and the transformer 'hunted' for a better ground and found it through the earth to the drainfield and the 'soiled' water, which led back to the bonded metal plumbing piping... ZAP!!!
Thanks , for giving me that link, Blues, now I know less than I did! Lol I can understand D/C current fairly good. Current comes out of one post on the battery, goes into a wire, goes and does it’s work, returns via wire to the other battery post! A simple guy like me can understand that. But with A/C apparently it’s going both ways , meeting itself on the way and going in circles around the wire! Or something like that! Lol As long as it doesn’t get too complicated, I can deal with house wiring. I just rewired my shop, because I couldn’t get a 50 amp circuit breaker for my panel, so I replaced the whole box! And I’m still alive! Bones
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