Currently there is no known connection between human activity and tornado formation and intensity.
The area of greatest tornado activity appears to be shifting northward. It is unknown how this might affect tornado intensity.
The factors affecting tornado intensity are not fully understood. But an increase in the intensity of the parent thunderstorm, often from encountering warmer, moister air can cause a tornado to intensify.
No machine is used. The intensity of a tornado is determined by a visual survey of the damage.
That is impossible as the Richter scale is for measuring earthquakes.
Fujita intensity scale
If you are referring to the Fujita scale, which rates tornado intensity base on damage, its inventor is Dr. Tetsuya Fujita.
December generally has the least tornado activity.
Tornado Activity is monitored by the National Weather Service.
The intensity of a tornado is estimated based on the severity of the damage it inflicts.
Tornado activity in the U.S. is monitored by branches of the National Weather Service.
The size of a tornado is determined by the width of the area over which it produces damage. This is not to be confused with the tornado's intensity.
The intensity of a tornado is rated based on damage done on the ground.