I know more than the average bear about electrical stuff, but I’m functionality unable to use a multimeter. For literally decades I’ve used an old Radio Shack voltmeter usually to check continuity when troubleshooting. I have now 2 cheap multimeters, both free, and I can’t figure out with 25 or more settings on the little selector how to do anything with it. Is there a short course online to get me started? Preferably NOT a YouTube video because I can read. Maybe a manual that can print out and study with a meter in hand.
The Multi refers to the three main things you want to measure: resistance in ohms (which is how you check for continuity: very high ohms generally means open circuit, low ohms means short circuit). Pressure in volts (usually two scales for DC and for AC,) I tend not to try and measure AC volts with a multi meter. Even 110v AC could kill you. Third is flow in amps which can also be a tad tricky. Mostly you don’t need to measure the amps flowing.
For model railroads it’s either just enough amperage or way too much. The various circuit breakers protect from way too much or at least are supposed to.
I use mine for ohms and DC volts only. I use the 25v DC range for train stuff. I use maximum ohms for continuity testing. That’s only two things you need to remember.
Really, it’s the electrical stuff you’re trying to measure you need to be aware of rather than what a multi meter can do. For model trains I recommend you learn the 25v DC and ohms and don’t try and use the other features unless you’re also fully comfortable with the voltages and currents you are trying to measure. Voltage only kills you if it punches enough amps through you at the same time.
The main problem with that Home Depot guide is the description of testing AC voltage. That’s not what they are describing. They are describing whether the appliance tested is capable of handing AC voltage. No actual voltage can be measured through the male end of a plug.
The warning that ought to be prominent but isn’t is the tag line at the end. Basically don’t stick your multi meter pins into a live socket in your house. It go boom. “Call an electrician” should be in bold all caps.
To use a multi meter safely you really need to know the limits of your electrical knowledge and stay well within those limits. The actual meter isn’t difficult to use for model railroading.
One of the two is the harbor freight meter. It didn’t come the manual. I’ll print it out and sit down and try to absorb it. My old Radio Shack meter still works for what I need (AC voltage for DCC and track continuity. ) Maybe I don’t need it for anything else. Still it’s going to be nice to see.
I don’t see how that is helpful to the OP. Every forum on the internet will have good and bad answers. Do we want this to be a forum of just bad answers?
Whenever there is a question in the forum about a train slowing down or not running at all, the obvious question, and the one the questioner never wants to consider is what is the voltage on the tracks?
if the OP intends to put decoders in older locos, measuring amperage is a useful thing to do. I’ve measured household current as well and am still here to tell about it and so is the meter.
The meters I have are clearly marked with ranges. I can’t imagine and MR scenairo where you wouldn’t know the range of voltage.
Continuity. Take a piece of sectional track. There is no continuity if you put a probe on the left and the probe on the right. Put it on two places on one rail and there is a buzz. Of course there is usually no need to test L & R unless you screwed up the feeders.
Resistors have color codes but if you can’t be bothered looking them up, start high and work your way lower and you won’t damage the meter.
Amps The thing to know about amps is that amps aren’t forced on anyone. It’s like drinking a daiquiri through a straw. You have to suck on the straw, it doesn’t force it down your throat. Like a short, if you drop a garden hose in the glass you can suck a lot more daiquiri or amps.
DCC voltage can me measured on the AC scale. It may not be as accurate, but when there are problems it’s not 13.4 vs 13.3 V, it’s 13.4 vs 8 V.
