Calibrate: Check or adjust the graduations of a quantitative measuring instrument.

Calibration: A set of operations that establish, under specified conditions, the relationship between the values of quantities indicated by measuring instrument or measuring system and the corresponding values realized by standards.

Calibration Point: One particular measurement in a sequence of measurements aimed at providing calibration.

Capillarity: The characteristic of a liquid to be raised or depressed in a tube of small bore. This action is caused by a combination of cohesive, adhesive, and surface tension forces.

Cavitation: Process in which small bubbles are formed and implode violently. This results in aggressive cleaning action in ultrasonic cleaners.

Celsius Temperature Scale: A temperature scale based on mercury in glass thermometer with the freezing point of water defined at 0 degree C and the boiling point of water defined at 100 degree C, both under conditions of normal atmospheric pressure.

Center of Instrument: The intersect point of the vertical, horizontal, and optical axis of a transit or similar instrument when perfectly calibrated.

Certify: Provide evidence for or authorize officially.

Certified Reference Material (CRM): Reference material, by a certificate, one or more of whose property values are certified by a procedure which establishes its traceability to an accurate realization of the unit in which the property values are expressed, and for which each certified value is accompanied by an uncertainty at a stated level of confidence (ISO Guide 30:1992).

Centripetal Force: The inward force on a body moving in a curved path around another body.

CGS System: The common metric system of units (centimeter-gram-second).

Characteristic: A property that helps to differentiate between items of a given population. Note: The differentiation may be either quantitative (by variables) or qualitative (by attributes).

Clinometer: An instrument used by surveyors in order to measure an angle of inclination or elevation.

Coefficient of Linear Expansion: The change in unit length in a solid when its temperature is changed 1 degree.

Coefficient of Volume Expansion: The change in unit volume of a solid when its temperature is changed 1 degree.

Cohesion: The intermolecular force that holds together the molecules in a solid or liquid.

Collimation: The process of aligning the optical axis of optical systems to the reference mechanical axes or surfaces of an instrument, or the adjustment of two or more optical axes with respect to each other.

Collimator: An instrument designed to produce collimated (parallel) rays of light usually equipped with displacement and tilt graticules.

Comparator: An instrument for comparing some measurement with a fixed standard.

Complex Vibration: The combination of two or more sinusoidal vibrations existing simultaneously.

Compound: Two or more substances combined in definite proportions by weight and united chemically.

Condensate: Steam which rises and cools to a liquid.

Conductivity:The transmission of heat or electricity or sound.

Conformity: Fulfillment of specified requirements.

Contacts: Elements used to mechanically make or break an electric circuit.

Continuous Duty: A device able to operate continuously with no off or rest period.

Contract Review: Systematic activities carried out by the supplier before signing the contract to ensure that requirements for quality are adequately defined, free from ambiguity, documented, and can be realized by the supplier.

Contractor: Supplier in a contractual situation

Convection: Transmission of energy or mass in a medium by movement of the medium itself.

Conversion Chart: Must be used to convert a parts per million reading to micromho or vice versa because the ppm scales are non linear and the micromho scales are linear. Because of the curve, there is no set ratio so one must refer to the chart.

Correction: The value added algebraically to the uncorrected result of a measurement to compensate for systematic error.

Corrective Action: Action taken to eliminate the causes of an existing nonconformity defect or other undesirable situation in order to prevent recurrence

Creep: The long term change in dimensional characteristics of a body under load, in an elastic force measurement device. This term refers to the change in reading which occurs when a constant load is applied for a period of time.

Critical Angle: The angle between and at which there is neither refraction or internal reflection.

Critical Size: For fissionable material, the minimum amount of a material which will support a chain reaction.

Cryogenic: The science of refrigeration pertaining to the methods for producing and measuring very low temperatures.