The phrase "a certain span" is correct and usable in written English.
It can be used to refer to a specific but unspecified length of time or distance.
Example: "The project will take a certain span of time to complete, depending on the resources available."
Alternatives: "a specific duration" or "a particular length".
The perception that stone beams could not exceed a certain span is coherent with the so-called size-effect theory of rock and concrete, which predicts that large elements are proportionally weaker than small ones.
While my following is quite diverse, by definition they are all within a certain span of political views.
We performed a sliding window analysis that compared structural and functional properties of adjacent neuron populations within a certain span of the cortical depth.
As soon as the subject gave an incorrect answer for all three trials for a certain span, the task was finished.
We also find that accumulative rainfall over a certain time span (or rainfall over a long time span) is an appropriate threshold for flash flood warnings in humid regions because the runoff is dominated by excess saturation.
A search for the terms "Alaska" and "bridges" would expose a certain $223 million span to Gravina Island (population 50) that critics call the "Bridge to Nowhere".
"People came to terms with the fact that a multinational has a certain life span".
"It's a way to create a communal reading experience, so people can experience it in a certain time span together," Mr. Horowitz said.
They might use machines to record how many times customer-service telephones ring before being answered or what percentage of requested repair parts they can deliver within a certain time span.
The theoretical potential is as an estimate of 'the physically usable energy supply over a certain time span in a given region.
As Chowdhury (2002) points out that allowing for a certain time span is critical, as most restructuring actions yield lagged results.
