What capacitors should I get or resistors to check ohms on my multimeter - Page 1
Forum section: electronics / testgear

author: psxpetey1
author_rank: Regular Contributor
timestamp: December 11, 2020, 04:46:44 am
content: I have a uni-t 61e and I think it may be acting up a bit.What kind of gear should I get to check all its ohms functions diods etc.It seems to be right on with voltages

author: wizard69
author_rank: Super Contributor
timestamp: December 11, 2020, 06:10:43 am
content: Quote from: psxpetey1 on December 11, 2020, 04:46:44 amI'm not sure if you are serious here but precision resistors would be a good start. If you just want to check and see if the unit is in the right ball park you can order what you need as components from just about any decent electronics distributor. Digikey has precision resistors from $0.66 to $50 in the 0.1% to 0.05% range.Such resistors wouldn't be consider calibration standards (unless this is a real cheap meter) but would be good enough to tell you if the meter is working at all on Ohms scale. It is worthwhile to have a few precision resistors lay about to proof resistance reading equipment. for example if working with equipment using RTD's it can be handy have a precision resistor to heck meter operation, this especially if pulling the RTD may take a good part of a day. The idea is that connection such a component to a resistance reading device should give you a well defined value on the meter.A quick edit:Check your leads!!! Just a couple of days ago I had trouble at work with a meter not working correctly and ended having to replace the meter leads. The do go bad and can be intermittent in strange ways.

author: psxpetey1
author_rank: Regular Contributor
timestamp: December 11, 2020, 03:02:29 pm
content: Quote from: wizard69 on December 11, 2020, 06:10:43 amI am serious and how would I check my leadsthe reason im asking is because I want to know what precision resistors I should buy and in what categories uni t 61e is autoranging

author: tggzzz
author_rank: Super Contributor
timestamp: December 11, 2020, 03:06:30 pm
content: Quote from: psxpetey1 on December 11, 2020, 04:46:44 amDefine "acting up a bit".Thenyou may be able to work out what tests to do.

author: AVGresponding
author_rank: Super Contributor
timestamp: December 11, 2020, 03:41:56 pm
content: You can check your leads by shorting them together on ohms range. If they show more than half an ohm or so, there's a problem.

author: psxpetey1
author_rank: Regular Contributor
timestamp: December 13, 2020, 05:13:24 am
content: Ohms seemed off but I can’t be sure as I don’t have precision gear

author: Fungus
author_rank: Super Contributor
timestamp: December 13, 2020, 07:04:49 am
content: This is on of the reasons whyeverybodyneeds more than one meter - so you can cross check them against each other when you suspect one might be "acting up".If you have two meters then you can use any old resistors.Even one of those crappy $4 DT830B meters would do.If you know anybody else with a multimeter then get together and compare them.

author: Noy
author_rank: Frequent Contributor
timestamp: December 13, 2020, 12:49:36 pm
content: DMm Check Plus + additional Cap PCB...

author: Fungus
author_rank: Super Contributor
timestamp: December 13, 2020, 04:01:20 pm
content: Quote from: psxpetey1 on December 13, 2020, 05:13:24 amWhat do you mean by "off"?If you short the leads is it near zero? If you measure a 10k resistor is it near 10k?You don't need precision gear to know if it's broken.

author: NoisyBoy
author_rank: Frequent Contributor
timestamp: December 13, 2020, 06:01:20 pm
content: And you need to think ahead to the next step, what if it is indeed off? Can it be calibrated, do you have the service manual or the tool to do it?Most cheap meter does not have a way to calibrate resistance measurement, even it is off, there is not much you can do unless you would do mental compensating calculation on every reading. These are throw-away meters that are built to a low price point.I suggest you first change the battery to see if it makes any difference, check for failing probes and wires as others have suggested. If not, buy a second good meter and compare the reading. If it is off, then I would suggest to retire it or pitch it.