What is the source and the current level (L1 or L2 or L3) of the AVIRIS data that you are using? Do you have any other information in the metadata regarding the units? Is it in raw DN values or Radiance or Reflectance? Depending on the level of the data the units would differ and therefore the min-max data value range. For example, the Surface Reflectance product typically has data values ranging from 0 to 1 (unitless). Attached links might be helpful.

https://www.harrisgeospatial.com/docs/preprocessaviris.html

https://aviris.jpl.nasa.gov/aviris/data_pipeline.html