Full formScience
IPKstands forInternational Prototype of the Kilogram
Full Form of IPK
What is IPK?
The International Prototype of the Kilogram (IPK) is a platinum‑iridium cylinder that served as the global standard for the unit of mass from 1889 until 2019. Manufactured by the International Bureau of Weights and Measures (BIPM) in France, it was the sole artifact defining the kilogram, and its mass was considered exactly one kilogram. In India, the IPK influenced the country’s metrology through the National Physical Laboratory (NPL), which maintained calibrated copies to ensure consistency in trade, industry, and scientific research. With the 2019 redefinition of the kilogram based on the Planck constant, the IPK is no longer the primary standard, but it remains a historical reference. Its role in India is evident in legal metrology, where precise mass measurements affect sectors like pharmaceuticals, agriculture, and gold trading. For competitive exams like UPSC or JEE, understanding the evolution of the kilogram and the IPK is relevant to questions on fundamental units and measurement standards. The IPK represents a pivotal shift from artifact‑based to constant‑based definitions in the International System of Units (SI).
IPK का फुल फॉर्म
अंतर्राष्ट्रीय किलोग्राम प्रोटोटाइप
Example
The National Physical Laboratory in New Delhi holds a national prototype of the kilogram that was calibrated against the International Prototype of the Kilogram to ensure accuracy in Indian trade.
IPK — frequently asked questions
What is the full form of IPK?
The full form of IPK is the International Prototype of the Kilogram, a platinum‑iridium cylinder that defined the kilogram until 2019.
Is the IPK still used as a standard in India?
No, the IPK was replaced in 2019 by a definition based on the Planck constant. However, India’s national prototypes derived from the IPK are still used for legal and industrial calibration.
Why was the IPK replaced?
The IPK was replaced because its mass drifted slightly over time due to surface contamination. The new definition based on fundamental constants provides greater stability and universal reproducibility.