These look excellent for accurate power measurement of Phase controlled elements IE. PSR 25. or...Pot + SSR-VR type controllers
Standard AV voltmeters and AC Current meters can give quite "off" readings ....then ,if you want to calculate power ,you have to multiply the two readings .
This does all , Voltage ,current and Power + there are optional models which also measure Power factor( not really an issue with Resistive elements) or Frequency ( might be handy if you're using a Genny)
MuRata is a well recognized manufacturer of meters ....been round about as long as me
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Not sure if they would be any good on Burst Fire Controllers ...but no body seems to have built any here anyway