| Products > Test Equipment |
| Looking for a multimeter with these functions |
| << < (7/11) > >> |
| tooki:
He’s asking what value you want to measure. And probably why. Other than identifying a gross short circuit on a power rail, its resistance is meaningless. It isn’t clear to me (and likely everyone else here) what it is you’re trying to accomplish. Like, what is it you think you learn from a resistance measurement of a circuit with non-ohmic components? (I am not asking this to be sarcastic or rhetorical, I am genuinely curious as to what insight you gain, or wish to gain, from such a measurement.) Correct me if I’m wrong, but I think you think that the numbers you get are in some way inherently meaningful. But they aren’t. The only thing you can do with them is compare them to other numbers from a similar meter. That is because the numbers are only “true” within the exact test conditions created by that meter. A meter that creates different test conditions will create totally different numbers with an active circuit. Neither one is more or less correct than the other, because they’re both specious. Testing in-circuit is always fraught with peril. You really need to know what you’re doing so you can know which results are valid and which aren’t — and when you have no choice but to remove a component from the circuit to measure it. Just today, I desoldered a few resistor networks and a transformer from a board in order to determine the resistor networks’ topology and the transformer specs. No way to do it in-circuit. |
| tonycstech:
What value i want to measure ? The resistance value of a1.8v circuit on an Nvidia GPU. What am i trying to accomplish ? Consistent reading with 99% of all hand held multimeters to match with FLUKE Values are meaningless ? I have to disagree. After doing so many of these i can tell what the problem is just by looking at the value. Testing in circuit is always.......? yeah, except that when i get the same reading using anything buyt FLUKE and bench meters, begs the question. Why not design your meter to get the same reading ? Other than that, FLUKE replied to me saying they "do not offer" firmware modifications. My argument is simple. 99% of all meters will give me one value while 1% will give me another. its a simple majority rule. I do not agree with the democracy in this regard because majority could be a bunch of idiots and there has to be a balance so the balance is: let me adjust voltage/current of the meter so i can get the same reading as other meters get. But we all know thats not going to happen so there is no point to continue this topic. Someone please lock it. |
| nctnico:
--- Quote from: tonycstech on September 30, 2024, 09:23:42 pm ---What value i want to measure ? The resistance value of a1.8v circuit on an Nvidia GPU. What am i trying to accomplish ? Consistent reading with 99% of all hand held multimeters to match with FLUKE --- End quote --- That is not going to happen due to differences in measurement currents and how the multimeters are constructed internally. The open voltage on various meters is different and some meters may have a true current source while others may have a simple series resistor to limit the measurement current (depending on range). Both methods will yield valid results when a true resistor is connected to the meter. However, when measuring in-circuit with semiconductors involved, you will get different readings between meters. |
| KungFuJosh:
--- Quote from: tonycstech on September 30, 2024, 09:23:42 pm ---I do not agree with the democracy in this regard because majority could be a bunch of idiots and there has to be a balance so the balance is: let me adjust voltage/current of the meter so i can get the same reading as other meters get. But we all know thats not going to happen so there is no point to continue this topic. Someone please lock it. --- End quote --- Yikes. That's inherently flawed thinking. As others have said, those readings are meaningless. The only time your in-circuit measurements have meaning is if you're comparing a known good DUT vs a faulty DUT (both identical circuits), under the same measuring circumstances. Then you can compare the values and ponder why the discrepancies. Without that specific comparison, you would need a schematic with in-circuit values for every device, and that doesn't usually exist. Altering a DMM as you suggested is called adjustment. Adjustments are made with a calibrated machine, usually specifically made for this purpose. Arbitrarily adjusting a DMM based on irrelevant noise will only guaranty degrading your DMM. |
| tonycstech:
i fixed nearly 100% of all devices that come to me with my inherently flawed thinking. Lucky or maybe i see what most people dont ? I dont even have autism to be this smart :P if anything, i see my self as plain stupid |O I knew this wouldn't go anywhere since the very 1st reply. Why am i still here ? For the same reason i have high success repair rate. Just cant let it go. |
| Navigation |
| Message Index |
| Next page |
| Previous page |