Sir TophamHatt Posted July 16, 2018 Share Posted July 16, 2018 Can anyone give me some basic pointers on how to use a multimeter? As in, I have no idea what setting to put the meter on or where to prod the prongs. Don't mind giving a simple task a go. For example, could I see how much power is running through the rails? If so, how do I do it? Link to post Share on other sites More sharing options...
RMweb Premium kevinlms Posted July 16, 2018 RMweb Premium Share Posted July 16, 2018 Can anyone give me some basic pointers on how to use a multimeter? As in, I have no idea what setting to put the meter on or where to prod the prongs. Don't mind giving a simple task a go. For example, could I see how much power is running through the rails? If so, how do I do it? Ok, the first question is what sort of multimeter do you have? A digital one is the easiest to get started on, but make sure you set to correct settings, otherwise it may have a very short life. Try this for starters. https://learn.sparkfun.com/tutorials/how-to-use-a-multimeter Link to post Share on other sites More sharing options...
Sir TophamHatt Posted July 16, 2018 Author Share Posted July 16, 2018 A digital one. It's a Gunsons Pocketmeter 2! Been in my toolbox for about 10 years. 1 Link to post Share on other sites More sharing options...
HLT 0109 Posted July 16, 2018 Share Posted July 16, 2018 I found this link to an instruction manual: https://www.yumpu.com/en/document/view/22122778/pocketmeter-2-gunson. I hope it helps. Harold. Link to post Share on other sites More sharing options...
jonhall Posted July 16, 2018 Share Posted July 16, 2018 Your first 3 lessons (and assuming DC control) 1) turn it clockwise 3 spots to 'V' '20' in the yellow section and put the two probes across a bit of track that you would expect to be live (i.e. a loco would move if put on it) you should get a voltage of about 12v (ish) 2) continue clockwise to V~ 200 in the lower blue section and put the two probes on the accessory output of a controller (the 16v output for point switching) you should expect a reading of about 16v 3) return to 'off' then anti clockwise to any of the 5 segments in the blue 'Ohm' section (the 200 is best). with the probes separate you should read '1'. Touch the two probes together and you should get close to '0' and may get a beeping noise (depending on the meter - it is quite a useful function). How would you use it in the modelling world? touch one probe to one end of a wire and the other probe to the other end, if you have continuity you get '0', and no continuity (i.e. a broken wire) '1'. You can also use it to check that neighboring pins on a plug aren't touching, which rails at a point are live, if the blades of a point are making contact with the stock rails. That is what most of us use 80+% of the time. Jon Link to post Share on other sites More sharing options...
RMweb Premium newbryford Posted July 16, 2018 RMweb Premium Share Posted July 16, 2018 3) return to 'off' then anti clockwise to any of the 5 segments in the blue 'Ohm' section (the 200 is best). with the probes separate you should read '1'. Touch the two probes together and you should get close to '0' and may get a beeping noise (depending on the meter - it is quite a useful function). The beeper will be the black section at about 5.30 on the face of the meter as pictured. The terminal on the left is only required when measuring amps above the 200mA range Cheers, Mick Cheers, Mick Link to post Share on other sites More sharing options...
cliff park Posted July 17, 2018 Share Posted July 17, 2018 This may be obvious, but just in case:- if measuring voltage put one probe on each 'leg' or wire. If measuring current you must connect the meter in series, ie disconnect a wire and connect the meter in place of it. When measuring resistance the circuit must be switched off, ie no power. With a digital meter polarity is irrelevant,it will show a negative if the wrong way round. If measuring a varying voltaage digital meters can be difficult because of the sample rate Link to post Share on other sites More sharing options...
Sir TophamHatt Posted July 17, 2018 Author Share Posted July 17, 2018 Thanks. Managed to light up some LEDs yesterday too, so that was exciting! I'll give some of this a try. Is there a way I can use the multimeter to see if a chassis is live? Link to post Share on other sites More sharing options...
RMweb Premium newbryford Posted July 17, 2018 RMweb Premium Share Posted July 17, 2018 Thanks. Managed to light up some LEDs yesterday too, so that was exciting! I'll give some of this a try. Is there a way I can use the multimeter to see if a chassis is live? Use the beeper to check for connections between both tracks and both motor terminals. Make sure you get a good contact on the chassis as the blackening can sometimes cause a bad connection Link to post Share on other sites More sharing options...
RMweb Premium kevinlms Posted July 17, 2018 RMweb Premium Share Posted July 17, 2018 Use the beeper to check for connections between both tracks and both motor terminals. Make sure you get a good contact on the chassis as the blackening can sometimes cause a bad connection Better is use the Ohms setting (the 200 one), as most of the continuity settings on multimeters will beep, on a few ohms. Much better to test on the lowest available ohms setting, to find the real resistance. Can't test at present, as mine is in the car and its dark out there! Link to post Share on other sites More sharing options...
RAF96 Posted July 17, 2018 Share Posted July 17, 2018 If the value being checked is unknown, set the range to the highest setting and work backwards. Some meters are auto-ranging and auto-polarity which is handy. The - ... symbol means DC and the ~ symbol means AC or at a push roughly DCC. Three basic measurements... Volts - parallel connection twixt pos and neg (DC) or live and neutral (AC). Amps - series connection with the component being checked for current draw. Note separate probe lead connection for 10A DC measuring, use this for loco motor stall current checks. Ohms - parallel connection across component being measured. If a component is wired in then one end needs disconnecting or you are likely measuring the whole circuit resistance. Rob Link to post Share on other sites More sharing options...
AndyID Posted July 17, 2018 Share Posted July 17, 2018 Take care with the 10 amp connection. That meter has no fuse. Link to post Share on other sites More sharing options...
Sir TophamHatt Posted July 18, 2018 Author Share Posted July 18, 2018 Just to circle back to this. Used it yesterday to test an LED that went... well, very bright then very dark very quickly. Brill! Link to post Share on other sites More sharing options...
RMweb Premium kevinlms Posted July 18, 2018 RMweb Premium Share Posted July 18, 2018 Just to circle back to this. Used it yesterday to test an LED that went... well, very bright then very dark very quickly. Brill! https://www.engineersgarage.com/tutorials/led-testing-using-multimeter Link to post Share on other sites More sharing options...
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