Conversion from Cubic centimeters per minute to Fluid ounces per hour

Information about the Cubic centimeter per minute (cm³/min)

The cubic centimetre per minute is a unit of volumetric flow rate equal to one cubic centimetre passing a point every minute. Its symbol is cm³/min, and since a cubic centimetre is a millilitre, mL/min means the same thing. It is the standard unit of controlled gas flow in laboratories and in the semiconductor industry.

That industry gave it an abbreviation of its own: sccm, standard cubic centimetres per minute. The word standard matters, because a gas expands and contracts with temperature and pressure, so a volume flow means nothing until the conditions are pinned down. A mass flow controller set to 50 sccm delivers a fixed number of molecules per minute regardless of what the downstream pressure does, which is precisely what a deposition or etching process requires.

A silicon wafer passing through a plasma etcher meets several such controllers at once — argon at a few hundred sccm, a reactive fluorine compound at tens, oxygen at a handful — and the recipe that defines the process is essentially a list of these numbers against time. Repeating a process in another factory means reproducing the same flows.

Chromatography and gas analysis use the unit at the low end. Helium carrier gas through a capillary column runs at one or two cubic centimetres per minute, a flame detector burns hydrogen at thirty and air at three hundred, and a mass spectrometer's inlet is designed around a flow the vacuum pumps can cope with.

Liquids appear here as well, particularly in analytical chemistry and medicine. A high-performance liquid chromatography pump runs at 0.2 to 2 cubic centimetres per minute, and an intravenous infusion of 100 millilitres over an hour is 1.67 cubic centimetres per minute. In both cases the small, steady rate is what allows the result to be reproduced.

Sixty cubic centimetres per minute is one cubic centimetre per second, and a thousand is a litre per minute. So a typical mass flow controller set to 500 sccm is delivering half a litre of gas a minute — about the volume of a soft-drink bottle, which is a helpful way to picture what an invisible gas line is actually carrying.

One cubic centimetre per minute equals one millilitre per minute, about 0.01667 cubic centimetres per second, or 0.001 litres per minute.

Information about the Fluid ounce per hour (fl oz/h)

The fluid ounce per hour is a unit of volumetric flow rate equal to one imperial fluid ounce passing a point every hour. Its symbol is fl oz/h. An imperial fluid ounce is 28.413 millilitres, so an hour at this rate delivers about two tablespoons — a rate slow enough that it is measured by what has collected, not by what is moving.

Slow feeding and slow dosing account for most of its use. A drip feeder on a bird cage, a wick humidifier, a fragrance diffuser and a slow-release fertiliser injector on a greenhouse line all move liquid at a few fluid ounces per hour, and the reservoir capacity divided by that rate gives the interval between refills.

Domestic appliances are described by it in older British literature. A paraffin heater consumes a few fluid ounces per hour, a wick lamp rather less, and an oil-filled stove was once sold with its consumption stated exactly this way so that a household could calculate how long a gallon would last through a winter evening.

Evaporation and leakage measurements fall here too. Water lost from an open tank, brake fluid seeping past a seal, or condensate collected from a small cooling coil are all quantified per hour, because that is the shortest period over which enough accumulates to measure in an ordinary graduated cylinder.

The unit's usefulness lies in matching the observation to the human timescale. Nobody watches a drip for a second; a technician checks a container after an hour, a shift or a night, and expressing the rate per hour lets the observed volume be divided by the elapsed hours with no further arithmetic.

For orientation, 160 fluid ounces make an imperial gallon, so one fluid ounce per hour fills a gallon in a little under a week. Thirty-five fluid ounces per hour is about a litre per hour, and sixty fluid ounces per hour is one fluid ounce per minute.

One fluid ounce per hour equals about 28.41 millilitres per hour, about 0.02841 litres per hour, or about 0.01667 fluid ounces per minute.