What procedure(s) are you using for oven/chamber uniformity mapping?
I don't see anything for this in my old version of GIDEP.
ASTM D7969 - 16
Standard Specification for Gravity Convection and Forced Ventilation Ovens
AMS 2750E
I found Vaisala to provide very useful information regarding chamber mapping requirements:
https://www.vaisala.com/sites/default/files/documents/LSH-8-Steps-to-Mapping-Validation-Project.pdf