Both my multimeters will only measure current up to 10A. What
kit would you recommend to measure higher currents, up to about
40A? Build yourself a shunt. Take a piece of #14 or #12 bare
copper wire about 6 inches long and connect it to robust
terminals (enough to handle your max current). If the shunt gets
warm at the currents you work with, it won't be accurate and you
will need to use heavier wire. Then use small wire and tap off
the shunt near each end, but not touching the big terminals
(like this): The "#" denotes the large connectors, the "|"
denotes the small wire. The "---" denotes the bare copper wire
shunt. Now, connect the small wires to your voltmeter on the
millivolts scale and apply 2 different known currents to the
shunt and see what millivolts you get for each. Then do a first
order (linear) calibration and you have your current meter.
Alternatively, you may want to check out a local college or
technical school and see if they have any high current shunts
left over from the "good old days". T