# COMPRESSION RATIO

 In an internal combustion engine, the ratio of the volume of combustion space at bottom dead center to that at top dead center.

## Related Terms

### PISTON DISPLACEMENT

The volume which a piston in a cylinder displaces in a single stroke, equal to the distance the piston travels times the internal cross section of the cylinder.

### PINT

Abbreviated pt. 1. A unit of volume, used in the United States for measurement of liquid substances, equal to 1/8 U.S. gallon, or 231/8 cubic inches, or 4.73176473 10 4 cubic meter. Also known as liquid pint (liq pt). 2. A unit of volume used in the United States for measurement of solid substances, equal to 1/64 U.S. bushel, or 107,521/3200 cubic inches, or approximately 5.50610 10 4 cubic meter. Also known as dry pint (dry pt). 3. A unit of volume, used in the United Kingdom for measurement of liquid and solid substances, although usually the former, equal to 1/8 imperial gallon, or 5.6826125 10 4 cubic meter. Also known as imperial pint.

### PIEZOMETER

1. An instrument for measuring fluid pressure, such as a gage attached to a pipe containing a gas or liquid. 2. An instrument for measuring the compressibility of materials, such as a vessel that determines the change in volume of a substance in response to hydrostatic pressure.

### PACKAGING DENSITY

The number of components per unit volume in a working system or subsystem.

### OUTPUTMETER

Analternating-currentvoltmeter connected to the output of a receiver or amplifier to measure output signal strength in volume units or decibels.

### NUCLEUS COUNTER

An instrument which measures the number of condensation nuclei or ice nuclei per sample volume of air.

### MODULUS OF RESILIENCE

The maximummechanical energy stored per unit volume of ma-terial when it is stressed to its elastic limit.

### MOHR CUBIC CENTIMETER

A unit of volume used in saccharimetry, equal to the volume of 1 gram of water at a specified temperature, usually 17.5 C, in which case, it is equal to 1.00238 cubic centimeters.

### MINIM

A unit of volume in the apothecaries' measure; equals 1/60 fluidram (approximately 0.061612 cubic centimeter) or about 1 drop (of water). Abbreviated min.

### MILLILITER

A unit of volume equal to 10 3 liter or 10 6 cubic meter. Abbreviated ml. Also known as mil.

### Related questions

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