There should be a known rate of error that can be used in evaluating the results.

This process deposits charges into the granules, which in a dark room would slowly decay away at a known rate.

The solution to be analyzed is injected into the flame at a constant, known rate.

Typically these are processes that occur with a given known rate.

There is an electronic timebase that "ticks" at some known and accurate rate.

So we have a controlled and known rate of inflation within the system.

The moving-filter collection medium ("tape") is assumed to move across the deposition area at a constant, known rate.

Substitute the known rates of change and the known quantities into the equation.

What is the known or potential rate of error?

But the toxic agents volatilized at a known rate.