Conversion from Cubic millimeters per minute to Cubic centimeters per second

Information about the Cubic millimeter per minute (mm³/min)

The cubic millimetre per minute is a unit of volumetric flow rate equal to one cubic millimetre passing a point every minute. Its symbol is mm³/min. It measures flows so slight that a whole minute yields a volume the size of a coarse grain of salt, and it exists because a great deal of precision engineering happens at exactly that pace.

Electrical-discharge machining is the classic user. A wire eroder cutting hardened tool steel removes 20 to 100 cubic millimetres per minute, and a sinker eroder finishing a mould cavity may remove less than one. The rate is the whole economics of the process: a die that takes eight hours to cut cannot be quoted like one that takes eight minutes, and the removal rate is what separates them.

Grinding and honing are described the same way when the tolerance is tight. A creep-feed grinder roughing a turbine blade root runs at hundreds of cubic millimetres per minute per millimetre of wheel width, but a final spark-out pass approaches zero by design, because the last few micrometres must come off without heating the workpiece.

Adhesive and solder-paste dispensing lives here too. A dot of adhesive on a circuit board is a fraction of a cubic millimetre, and a dispensing valve laying a bead is programmed by rate so the bead stays the same width as the head speeds up and slows down around corners. Underfill, conformal coating and potting are all specified in this unit or its microlitre twin.

Biology and medicine borrow it for slow perfusion. Organ-on-a-chip devices, microdialysis probes and slow-release implants move fluid at single-digit cubic millimetres per minute, and cerebrospinal-fluid production in an adult is about 350 to 500 millilitres a day, which is roughly 250 to 350 cubic millimetres per minute — a useful reminder that the body itself works at this scale.

Sixty cubic millimetres per minute is one cubic millimetre per second, and a million is one litre. Put together, that means a flow of one cubic millimetre per minute would need almost two years to fill a one-litre bottle.

One cubic millimetre per minute equals 0.001 millilitres per minute, about 0.01667 cubic millimetres per second, or one microlitre per minute.

Information about the Cubic centimeter per second (cm³/s)

The cubic centimetre per second is a unit of volumetric flow rate equal to one cubic centimetre passing a point every second. Its symbol is cm³/s, and because a cubic centimetre is exactly a millilitre, the same rate is often written mL/s. It sits in the gap between the laboratory and the workshop: small enough to measure with a syringe, large enough to see.

Physiology uses it constantly. Resting cardiac output of five litres a minute is about 83 cubic centimetres per second, urine production is roughly 0.017, and a quiet breath moves perhaps 500 cubic centimetres over two seconds. Because the human body deals in volumes of this order, medical devices from ventilators to infusion pumps are calibrated in it.

Gas flow measurement adopted it early. A rotameter — the tapered glass tube with a float that appears on every laboratory bench — is graduated in cubic centimetres per second or per minute, and the float position gives the flow directly. Since a gas expands, such readings are meaningful only when the temperature and pressure are stated, which is why standard conditions accompany them.

Engines make an instructive example. A four-stroke engine of 2,000 cubic centimetres running at 3,000 revolutions per minute draws air through its intake at 1,500 cubic centimetres per revolution, or 75,000 cubic centimetres per second at 100 per cent volumetric efficiency. The mass air-flow sensor in the intake measures a quantity closely related to this, and the fuelling calculation depends on it.

Laboratory chromatography and analysis are specified here as well. A gas chromatograph column carries carrier gas at one to two cubic centimetres per minute, while a detector's make-up flow may be twenty or thirty, and the ratio between them determines the shape of the peaks the instrument reports.

The unit's convenience comes from the size of the cubic centimetre itself. A thousand of them make a litre, so a thousand cubic centimetres per second is a litre per second — a bath filling in about two minutes. Anything a person can pour by hand lies within a factor of a hundred of this rate.

One cubic centimetre per second equals one millilitre per second, 0.001 litres per second, or 60 cubic centimetres per minute.