Nonconformity question

First, I don’t use the word “observation” because it is not defined in ISO 9000:2015.

Second, I would raise a non-conformity as being the equipment out of use and without being properly identified as such can promote inadvertent use. Something like:

Measuring equipment shall be identified in order to determine their status (ISO 9001:2015 clause 7.1.5.2b)).
When auditing the production area an equipment was found to be past due for calibration and without status identification, as such can promote inadvertent use.
During the audit a UV-VIS  spectrometer was found to be past due for calibration in the production area. When questioned, the department manager said that the equipment was out of order; but there is no warning sign indicating that.

You can find more information below:

• Monitoring and Measurement Equipment Control - https://advisera.com/9001academy/blog/2014/05/06/monitoring-measurement-equipment-control/
• Free online training ISO 9001:2015 Foundations Course – https://advisera.com/training/iso-9001-foundations-course/