And if you are testing the tension in a strung racket the size of the head, string, pattern, vibration dampening devices, among other things may make the tension appear to be non linear. There is not just one way to test tension in a strung racket. You usually have to include all those variables in order to get accurate readings.
Everyone has the right to be stupid... it's just that some people abuse the privilege...
Balance - 31.0 cm, Weight - 358 g, SW - 346 Kgcm^2