For a start, your claim as to "what they are sold as" is incorrect. From the documentation ...They are sold as an accurate way to measure power consumption which they do not do. Goods must be fit for the purpose which the Owl is not.
I would say that the product is more than 'fit for the purpose' that they describe.Our products are designed to provide useful indication information showing both live and historic data and usage / generation patterns. It is not meant to be or to replace metering products. Due to the limitations of the current clamp sensors, all products of this type will have a level of inaccuracy. These sensors only measure the current flowing, they cannot measure the voltage or the power factor and assumptions therefore have to be made (Our defaults are 230v and PF 1.0) in the calculations. Equipment capable of such measurements would be relatively costly and have to be wired into the circuit by an electrician.
I disagree. "What I have done" is no more than what is described under "Improving Accuracy" in their documentation.John what you have done is beyond the capabilities of the average buyer.
The procedure is hardly rocket science. If one wants to bother with PF, one first observes one's meter over a period of time to ascertain one's 'average PF', and the programme the Owl accordingly. In the case of my installation, it's about 0.994 - so, if that is typical of domestic installations', there would only be a very trivial error if one stuck with the Qwl's default of PF=1 (e.g. if one'd meter did not provide PF information). One then runs the Owl for a period of time (a week or so is usually adequate) whilst simultaneously observing kWh consumption per the meter - and then simply adjusts the programmed voltage programmed into the Owl pro-rata to the ratio of Owl / meter kWh totals over the observation period in question.
However, as above, even if one stays with the default settings, the Owl will still "provide useful indication information" (the stated purpose) to an accuracy adequate for most people, and would certainly be more than accurate enough to indicate any significant 'changes'.