Is there a better design?

Hello Folks,

I have been working on a database design for my company which is in the filed of calibration. I have came up with the attached design and i need you to give me feedback.

we're a small company that is doing on site calibrations for temperature, pressure and other sensors and issue certificates.

all i want to do is to implement a software that will ease the management of the massive and increasing data that we have.

i want to automate the issuing of certificates and keep their results in a MySQL database.

Attachment 13958

Attached Images

design.png (104.5 KB)