As a mechanical engineer, I was looking for a measuring instrument that could assess drainage patterns, for a builing site. Roughly I was looking for 2% precision in measurement of distance, angle and elevation. I did not need the precision needed to prepare legal property descriptions, which I consider the realm of land surveyors. For mechanical-engineering purposes, I only needed to estimate drainage flow rates, to determine the size of drainage pipes necessary.
I was very satisfied with the CST/Berger 54-200BN transit level. The benchmark measurements I made showed that it agrees within 1% of tape measurements for stadia distance, and is well within 1% for typical angle measurements that I am likely to make. It serves my purposes well, and it only costs a fraction of "total-station" instruments, which may be better suited for land surveyors.
Unlike more expensive products, the CST/Berger 54-200BN provides only a measurement. For engineering calculations, you are on your own. I needed to consult a Surveying textbook to code the necessary calculations into an electronic worksheet. I think such a skill is within the capability of many mechanical engineers. This effort required about one week of work, but allows me to transcribe simple transit measurements from a field book into a worksheet. From there I get the calculations necessary for reliable contour plots.