I am trying to verify that an electric meter pulser is putting out pulses correctly. My literature says that it puts out a 500 milisecond pulse, dry contact closure, it is being supplied with 10vdc on the common. I believe it is caled a Form A pulse??

My concern is that my Digital multi meter is not seeing that quick of a pulse and that i am simply missing them, due to the DMM not "refreshing" quick enough. I have no clue though, could just be a broken pulser.

Any input is appreciated......unless its disparaging....nobody likes that kind.

 

DMM's are pretty slow, not much use for time varying signals.

The simplest way to verify this pulse would be to connect an LED and resistor to the output.

 

Cool thanks, I didn't think of that. Great idea

 

500ms is fairly long, should be sufficient for a meter to at least respond, some meters like the Fluke have a linear bar display below the digits, this reacts at a faster rate than the digit display and can at least give a rough idea of output.
Max.

 

What kind of DMM do you have, and can you explain what you thought your DMM would actually do with a pulse input? Read the peak value perhaps, or read some kind of average, or maybe some other possibility. The feature you want might actually be there without you being aware of it. Unless it is a $3.99 model from Harbor Freight, accuracy is unlikely to be a problem.

 

Does your meter have a period setting and counter?

That would seem the most helpful.

The actual pulse length may not be important.

 

Of course the proper tool is an oscilloscope. Seeing is believing.

 

are you using your dmm on ac, or dc? ac should respond, vootage indicated might not mean anything, but presance of pulses should be indicated as a jump in voltage.

 

Sorry, I have a pretty nice Fluke. I guess the issue ended up being the pulser. I did read a pulse on another one. The question just came up in checking and before I threw the pulser out I wanted to be sure. I am a commercial electrician by trade but I am having to learn as I go about these "low voltage" issues.
I'll have more questions, so bolo.

 

I was going to say, my fluke 117 has this spec for continuity

Beeper on < 20 Ω off > 250 Ω; detects
opens or shorts of 500 μs or longer.

And the 112 it replaced was specced at 250uS