To re-scale a measurement, first you need to get to its measurement page.

This can be done by finding the measurement in any of the other pages of the site and clicking on the 'eye' button, or by clicking on it on the device page.

Scaling is configured by pressing the 'Edit Formatting & Scaling' button on the measurement page. You'll be taken to Formatting and Scaling

Find the 'Scaling' module (usually the second one in the list) and enter your new 'Measurement Minimum' and 'Measurement Maximum' values.

You may also want to check the incoming values for the scaling as well, in case there is an issue there. Having the wrong incoming values will result in a non-linear error in your scaling.