got mind blown about why Fluke has wrong design on T6
Fluke doesn't have a wrong design on the T6. They have what might be called "BATNEEC" (Best Available Technology Not Entailing Excessive Costs"). In other words, if you tried to design something better at the same level of practicality and manufacturing cost, you would be unable.
The fact that it works as well as it does is amazing. The fact that it doesn't work better is a limitation of physics. What you have to decide is, is this technology worthwhile and useful to you? Can it solve a problem you can't solve more easily another way?
Yup, actually, I'm not really sure if it was wrong design because as I said on my prev reply "as said by others". Just like you, I'm not an EE so i don't know either why I'm here but anyway, been dreaming to be a successful hobbyist and I have this project where I want to measure voltage non-invasive same as how CTs measure current non-invasive that's why I end up looking at capacitive voltage sensor to the Fluke Y6
Interesting, I have never heard of the acronym "BANTEEC" before. I do understand what you are getting at, but I am also wondering if the T6 concept was also a limiting factor in the design and it is possible to improve the accuracy just not in the T6 package.
I would say that the T6 is aimed at domestic, commercial and industrial electricians and in that respect accuracy isn't the highest priority. If I am fault finding and I read 110V, 115V or 120V, I don't really care, I know the voltage is there, so I move onto the next aspect of the circuit. What is important to me is ergonomics of the instrument and ease of use. Fluke already had the T5 which was popular, so making the T6 fit into the T5 case may have been their priority and sacrificed other aspects such as accuracy in lieu of that.
The time when I am really after some accuracy is power monitoring / analysis. At the moment voltage connections for these instruments are direct, but this has issues both with making the connections and leaving the instrument unattended whilst logging the data.
A contactless voltage pickup for this aspect would be great for me, it improves ease of connection and makes things safer, whether or not it is in the same head as the current clamp or a different sensor probably doesn't really matter. Not having the physical constraints of the T6 case, may mean the accuracy issues can be addressed.
Hioki are also going down the route of contactless voltage measurement, all be it at low levels at the moment.
https://www.hioki.com/en/products/detail/?product_key=6409http://hiokiusa.com/wp-content/uploads/pdf/33589-A_TA_SP0001E01.pdfThe only thing after that is to make it wireless and self powered from the current in the circuit under test, but I can hold off until the following weekend for that
Kind regards