I am not able to find category for testing & calibration services
Re: I am not able to find category for testing & calibration serv
As per your post, I think you want to target display network for this category. Since it is not available,you can make a custom affinity audience like this:
Add the placements that you think your relevant audience visit. I suggest that you add as much as possible placements here because it will help the AdWords system to get the right audience for you.
Hope that helps....!