Use of articles in the description of an experiment

Question

I am struggling a bit with the sentence describing the experiment we conducted:

The tensile tests were performed at the XX strain rate for the sample with the XX mm gauge part.

There are particular numbers instead of 'XX' but I've decided to omit them here. This is the beginning of the chapter, so I mention everything for the first time.

In my understanding, all articles highlighted in bold should be definite because we are talking about the specific rate and sample characterized by specific dimensions. However, at the same time, I have a feeling that something is wrong here with the articles.

Answer 1

Even though I don't know the specifics of your case, I would suggest this:

The tensile tests were performed at a XX strain rate for the sample with the XX mm gauge part.

1. The first indefinite article could be used since there may be infinite instances of such "XX strain rate".
2. That sample is indeed a specific one.
3. That "XX mm gauge part" is also specific.