The phrase "a volume of about" is correct and usable in written English.
It can be used when estimating or approximating a quantity or measurement, particularly in scientific or technical contexts.
Example: "The container holds a volume of about 2 liters, making it suitable for storing liquids."
Alternatives: "an approximate volume of" or "a volume roughly equal to".
On the platform three reactors are placed to reach a volume of about 0.3 m3 of active material inside the reactor chambers.
To distinguish between these models by in situ experiments we propose a microscopic system which uses two-photon excitation of fluorescence in a volume of about 0.5 μm3.
Approximately 500 ml of cerebrospinal fluid (CSF) is produced daily, with a volume of about 150 ml replaced three to four times everyday through the choroid plexus system for cushion the brain and spinal cord [1].
The CMS silicon tracker, at present under construction, will consist of 10 barrel layers and 2×9 end cap discs inside a volume of about 5.6 m length and 2.4 m radius.
Special emphasis will be given to the results of a recent high rate test, where the TOFPET ASIC has been tested with Hamamatsu S12642-0404PB-50 SiPM arrays coupled to matrices of LYSO Ce crystals (3.1x3.1x12 mm3 each), exposed to a 500 MBq activity of FDG radiotracer in a volume of about 0.5 cm3.
The brain is the largest known of any modern or extinct animal, weighing on average about 7.8 kg, more than five times heavier than a human's, and has a volume of about 8,000 cm3.
A volume of about 200 µl of stools (preferentially blood, mucus, rectal sputum when present) were transferred with a disposable pipette in a haemolysis glass tube of 5 ml containing 300 µl of distilled water.
The mice were sacrificed when the tumors reached a volume of about 1.5 cm.
At the end of sonication, the obtained fluids were accurately mixed, centrifuged at 3000 rpm for 10 minutes and resuspended in a volume of about 1.5 mL.
Each pin withdraws a volume of about 250 nanoliters and deposits a spot volume of about 0.6 nanoliters, with a diameter of approximately 90 to 130 μm.
When the tumors had reached a volume of about 150 mm3 (100 to 300 mm), mice were grouped according to tumor volume.
