The highest-quality standard in metrology or chemistry
A primary standard in metrology is a standard that is sufficiently accurate such that it is not calibrated by or subordinate to other standards. Primary standards are defined via other quantities like length, mass and time. Primary standards are used to calibrate other standards referred to as working standards.[1][2] See Hierarchy of Standards.
^Skoog, Douglas A., Donald M. West and F. James Holler. "Fundamentals of Analytical Chemistry 8th ed." Harcourt Brace College Publishers. 1995 ISBN 0-03-035523-0
^Holt Science and Technology: Physical Science. Ed. Rinehart and Winston, Inc. Holt. Holt McDougal (July 2000). ISBN 978-0-03-051957-4.
A primarystandard in metrology is a standard that is sufficiently accurate such that it is not calibrated by or subordinate to other standards. Primary...
telecommunications, a primary time standard is a time standard that does not require calibration against another time standard. Examples of primary time, (i.e....
Preparing standard solutions require standards with known amount of analyte. Analytical standards can be categorized into Primary or Secondary standards. Primary...
The caesium standard is a primary frequency standard in which the photon absorption by transitions between the two hyperfine ground states of caesium-133...
calibrate a mass measurement instrument such as a Kibble balance as a primarystandard for the kilogram mass. The kilogram was originally defined in 1795...
The Planetary Habitability Laboratory (PHL) is a research remote laboratory intended to study the habitability of the Solar System and other stellar systems...
are health based and the EPA sets two types of standards: primary and secondary. The primarystandards are designed to protect the health of 'sensitive'...
Standardization. There are a range of primarystandards that are commonly used across the industry, as well as secondary standards which are less frequently adopted...
calibrated and documented as offset values. For instance, K20, the US's primarystandard, originally had an official mass of 1 kg − 39 μg (micrograms) in 1889;...
of its profits come from Asia, Africa, and the Middle East. Standard Chartered has a primary listing on the London Stock Exchange and is a constituent of...
temperatures that approach absolute zero. The primarystandard for the United States, the National Institute of Standards and Technology (NIST)'s caesium fountain...
of phthalic acid. KHP is slightly acidic, and it is often used as a primarystandard for acid–base titrations because it is solid and air-stable, making...
State primarystandard for the unit of surface density of heat flux (GET 172–2008). In 2013, the Institute develops the State primarystandard for the...
seven-nine years are considered primary education. The International Standard Classification of Education considers primary education as a single-phase where...
precedes secondary schooling. The International Standard Classification of Education considers primary education as a single phase where programmes are...
A frequency standard is a stable oscillator used for frequency calibration or reference. A frequency standard generates a fundamental frequency with a...
resulted in CRTs using primaries that deviated significantly from the original standard. Currently, ITU-R BT.709-5 primaries are typical for high-definition...
not reference any other standards. Secondary standards are calibrated with reference to a primarystandard. Working standards, used to calibrate (or check)...
A gold standard is a monetary system in which the standard economic unit of account is based on a fixed quantity of gold. The gold standard was the basis...
A standards organization, standards body, standards developing organization (SDO), or standards setting organization (SSO) is an organization whose primary...
detectors and filters used. For each photometric system a set of primarystandard stars is provided. A commonly adopted standardized photometric system...
Standard Chinese (simplified Chinese: 现代标准汉语; traditional Chinese: 現代標準漢語; pinyin: Xiàndài biāozhǔn hànyǔ; lit. 'modern standard Han speech') is a modern...
the primary Imperial yard standard had partially been destroyed in 1834, a new standard of reference was constructed using copies of the "Standard Yard...
A standard certificate of airworthiness is a permit for commercial passenger or cargo operation, issued for an aircraft by the civil aviation authority...
algebra, does not distinguish between primary keys and other kinds of keys. Primary keys were added to the SQL standard mainly as a convenience to the application...
down to less than 1 millisecond. The frequency standard of the clock is based on the primarystandard used by Japan's Communications Research Laboratory...
Standard temperature and pressure (STP) or Standard conditions for temperature and pressure are various standard sets of conditions for experimental measurements...
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