The phrase "after a certain length" is correct and usable in written English.
It can be used to refer to a specific duration or measurement that is not precisely defined but is understood to be significant in context.
Example: "The material will begin to show signs of wear after a certain length of time."
Alternatives: "after a specific duration" or "after a defined period".
Reducing the screen timeout length, which switches off the screen after a certain length of inactivity, can also help.
"We studied how animals stop reacting to a stimulus after a certain length of time," she said.
The company's Maestro Eco-Timer (about $48) automatically shuts off power after a certain length of time, making it useful for bathroom fans and vestibule lights.
Various sorts of technical solutions are being explored, ranging from music that would "expire" after a certain length of time to coded "watermarks" which might prevent or restrict digital copies from being made.
Female wolf spiders carry their egg sacs attached to the spinnerets and instinctively bite the egg sac to permit the young to emerge after a certain length of time has elapsed.
If you stood with your feet wide apart and faced the North Star, he explained, you would, after a certain length of time, begin to sense the motion of the earth in the night sky as it turned with you aboard.
After reaching a certain length, the occurrence of neurite branching and turning eventually led to perpendicular and/or disorganized growth.
I am reminded of a suspension cable where after the span reaches a certain length most of the strength required is to support the weight of the cable itself.
After repeating this cycle for a certain length of time, we collect particle data and compute the cosmic ray spectrum.
These results suggest that polymer segments crystallize near Tpoly after having grown longer than a certain length during polymerization.
Luminous paint, paint that glows in the dark because it contains a phosphor, a substance that emits light for a certain length of time after exposure to an energy source, such as ultraviolet radiation.
