Is my multimeter broken?... - Page 1
Forum section: electronics / testgear

author: Flydigital
author_rank: Newbie
timestamp: September 06, 2014, 11:38:21 am
content: ..or am I not using it correctly?I'm totally new to this but starting at the beginning I'm learning about Ohms law, voltage etc and how to use my multimeter correctly.Here's the meter:When doing a current reading I think this may be faulty on some of the dials, specifically the 20m DCA dial.Here's why.I make a simple circuit. 9volts with a 200k resistor. That's it. I put the multimeter in the circuit and put the dial to 200µ DCA and get a reading of about 45µA: 0.000045A - OK so far so good.Then I place a much lower resistor in the circuit - swap the 200k for 1k. So I should expect 9mA, so I move my dial to the 20m notch - anything up to 20mA?. When I switch to that setting, before closing the circuit it already start giving out numbers, slowly climbing up..3.34,...4.56,...8.67...etc. When I close the circuit the numbers freeze and then jump to 1 and sticks there.Should I get a new / better meter or am I using it incorrectly?Thanks for any guidance!

author: rolycat
author_rank: Super Contributor
timestamp: September 06, 2014, 02:18:40 pm
content: Very likely a fault, particularly if the other DC current ranges are still working correctly. Have you confirmed the value of the 1k resistor on the ohms range?If you can afford it, a better multimeter would certainly be a good idea. If you set the country flag in your forum profile it will be easier for people to provide advice about where to buy from.A decent meter which you can pick up for $18 or less on eBay is the Uni-T UT136B. Lightages has done a review which you can find on the forum.If you can afford to spend a little more, Franky (iloveelectronics on this forum) is an excellent international source for good value meters. He has an eBay store, but it may be cheaper to contact him directly. Two meters he has for sale are the Digitek DT-2843R at around $44 or the Uni-T UT139C for around $50.

author: Lightages
author_rank: Unknown
timestamp: September 06, 2014, 03:29:30 pm
content: As rolycat has implied, that meter is nice a cheap but ironically not for beginners as they have no idea of the dangers of it and the pitfalls of its design. Spend a few bucks more and get something much more reliable.

author: Flydigital
author_rank: Newbie
timestamp: September 08, 2014, 06:12:15 pm
content: Thanks! I'm in the UK but will take a look at those meters.cheers.

author: retiredcaps
author_rank: Super Contributor
timestamp: September 08, 2014, 06:22:16 pm
content: You can try fixing your existing meter?? Take it apart and check the rotary switch to see if there is any debris. Check the PCB for contamination, solder bridges. Often these 830 style meters are all poorly assembled and made.

author: German_EE
author_rank: Super Contributor
timestamp: September 09, 2014, 05:00:46 pm
content: Just as a quick check, disconnect the meter probes and try the meter on every range. On the low volts ranges (especially AC) you might see some flickering of the digits because of hum and noise pickup but on current you should see 0000 and ohms will indicate over range.If you see anything else on the display then maybe you have an internal short circuit or, perhaps, contamination on the meter PCB.