Hi!
Ok, another obscure sort of subject here for the extra-knowledgeable!!
I'd like to calibrate my arc welder to some degree...it can put out anywhere from 50 to 105A DC, and the scale it has on it is just not accurate. Of course, my DMM will only handle 10A max, and I don't have the means of obtaining a clamp-on meter or anything.
I've thought up a few schemes, from measuring the VOLTAGE at the plates being welded and working back, using the resistance (out, because this is probably a constant-current device, I'm thinking) to placing something like copper pipe in series with one of the electrodes and setting up a shunt system with the DMM (risky if you don't get it just right!). I do have an old D'Arsonval meter movement that I might be better off trying this with....I can easily measure its internal resistance, etc.
Any thoughts on how to do this, in a way that is fairly safe and may give somewhat reliable results? I'm leaning toward the shunt idea....a piece of copper pipe would give the low resistance needed, and can be cut to adjust its resistance....or maybe that's just a "pipe dream"?
I just need to mark 3 or 4 locations of known amperage to refer to
Thanks!
Ok, another obscure sort of subject here for the extra-knowledgeable!!
I'd like to calibrate my arc welder to some degree...it can put out anywhere from 50 to 105A DC, and the scale it has on it is just not accurate. Of course, my DMM will only handle 10A max, and I don't have the means of obtaining a clamp-on meter or anything.
I've thought up a few schemes, from measuring the VOLTAGE at the plates being welded and working back, using the resistance (out, because this is probably a constant-current device, I'm thinking) to placing something like copper pipe in series with one of the electrodes and setting up a shunt system with the DMM (risky if you don't get it just right!). I do have an old D'Arsonval meter movement that I might be better off trying this with....I can easily measure its internal resistance, etc.
Any thoughts on how to do this, in a way that is fairly safe and may give somewhat reliable results? I'm leaning toward the shunt idea....a piece of copper pipe would give the low resistance needed, and can be cut to adjust its resistance....or maybe that's just a "pipe dream"?
I just need to mark 3 or 4 locations of known amperage to refer to
Thanks!