However, I don’t have direct access to external PDFs or a database of specific model manuals unless they are publicly indexed.

Since the ZY-8068 is often a "white-label" product (manufactured by one factory and branded by many), finding a PDF specifically titled "ZY-8068 Manual" can be difficult.

Because these units are often rebranded by different industrial suppliers, you can find official documentation through:

Users set a "coefficient" or "ratio" that translates the sensor pulses into a specific unit of measurement (e.g., meters or feet).