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<blockquote data-quote="SeanDub" data-source="post: 4656184" data-attributes="member: 568046">Take the results however you want. The owners manual says it has +/-&nbsp; 5% uncertainty for the AC current measurement. That means the current reading would be between 53.865 and 59.22 (+/- 5% from 56.4). That means the power could be between 3819 watts and 4199 watts, not considering the uncertainty of the AC voltage reading because I don&#039;t have that manual.But let&#039;s assume it is also around 5%. Therefore, that reading could be between 67.355 and 74.445. Therefore, coupled with the uncertainty of the AC current reading, the power could have been anywhere between 3609 watts and 4409 watts.Then we can look at the impedance the power was produced at. That calculation is voltage/current. So that impedance could have been anywhere between 1.14 and 1.38 ohm, which isn&#039;t much of a difference.So, the meter does have uncertainty, as does any meter, especially a meter to be purchased by a consumer/enthusiast. Your comment begs the question - how many of these clamp tests are worth anything? Because then you get into real power vs. imaginary power, power triangles, and the issue of impedance rise introducing imaginary power.</blockquote>

[QUOTE="SeanDub, post: 4656184, member: 568046"] Take the results however you want. The owners manual says it has +/- 5% uncertainty for the AC current measurement. That means the current reading would be between 53.865 and 59.22 (+/- 5% from 56.4). That means the power could be between 3819 watts and 4199 watts, not considering the uncertainty of the AC voltage reading because I don't have that manual. But let's assume it is also around 5%. Therefore, that reading could be between 67.355 and 74.445. Therefore, coupled with the uncertainty of the AC current reading, the power could have been anywhere between 3609 watts and 4409 watts. Then we can look at the impedance the power was produced at. That calculation is voltage/current. So that impedance could have been anywhere between 1.14 and 1.38 ohm, which isn't much of a difference. So, the meter does have uncertainty, as does any meter, especially a meter to be purchased by a consumer/enthusiast. Your comment begs the question - how many of these clamp tests are worth anything? Because then you get into real power vs. imaginary power, power triangles, and the issue of impedance rise introducing imaginary power. [/QUOTE]

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