The phrase "a span of approximately" is correct and usable in written English.
You can use it when describing a range of time, distance, or other measurable quantities that are not exact.
Example: "The project will take a span of approximately three months to complete."
Alternatives: "a range of about" or "an interval of roughly".
In the decades following World War II, the French economy was guided by a succession of national plans, each covering a span of approximately four to five years and designed to indicate rather than impose growth targets and development strategies.
It was to consist of 19 pointed arches, each with a span of approximately 24 feet (7 metres), built on piers 20 feet (6 metres) wide; a 20th opening was designed to be spanned by a wooden drawbridge.
The new vents of the 2014 eruption are located to the south of the 1979 eruption craters, distributed almost linearly along a span of approximately 800 m (Figs. 1, 2).
Figure 3a displays the waveforms of E z within a time span of slightly more than 1 s starting at 07:56:32.4290 UT, and Figure 3b shows the magnified waveform over a span of approximately 40 ms, corresponding to the black bar (07:56:32.429 to 07:56:32.469 UT) in Figure 3a, in order to highlight the details of the waveform.
Some of the qualities that appear associated with better outcomes include timing the interventions to co-occur with specific developments in child behaviors, teaching over a span of approximately 10 12 sessions, and designing lessons to be culturally sensitive to individual families.
For two years hundreds of people in Belgium saw what Kean describes as "a majestic triangular craft with a span of approximately a hundred and twenty feet and powerful beaming spotlights".
It is a catadromous crustacean with a life span of approximately two years.
The repeatability of the method was evaluated by double analysis of a certain mustard sample during 11 series over a time span of approximately 6 weeks.
This interval corresponded to a collinear span of approximately 926 kb of the B. rapa genome, containing 204 putative genes on chromosome A10 (Bra008819 to Bra009023).
The changes in total fruit and low GI fruit intake ranged from −3.7 to 3.2 servings per day and −3.1 to 2.7 servings per day, respectively, a substantial span of approximately six servings of low GI fruit per day.
We modified our algorithm in such a way that genes were considered to be expressed, if a transcript is either present during the time point of interest or during a time span of approximately 12 hours prior to this time point (concerns 12 preceding samples of Bozdech data set and 2 preceding samples of Le Roch data set).
