How to get a reliable wyfi strength measurement and any suggestions on increasing distance.

Not questions that come with easy answers.

 

You need an appropriate wifi client (receiver) to check the strength of the wifi from your router, if that is what you want to know.

 

Increasing distance doesn't mean much. Wifi strengths are down to standards and legal limits.

 

To stretch the wifi, you may have to add an "extender" to your network.

 

It all depends on having a clear explanation of what you really want to do rather than general questions.