Step-by-step explanation:
International standard: An international standard is a set of guidelines, specifications, or measurements that have been agreed upon by a group of countries or international organizations. These standards are typically used to ensure consistency and compatibility in areas such as trade, technology, and safety. International standards are often used to facilitate international trade and communication, and to ensure that products and services meet certain quality and safety requirements.
(ii) Primary standard: A primary standard is a standard that is considered to be the most accurate and reliable standard available for a particular measurement. These standards are typically used as the reference point for all other standards of that measurement. Primary standards are often used in scientific research and in the calibration of other standards.
(iii) Secondary standard: A secondary standard is a standard that is used to calibrate other instruments or standards. It is typically less accurate than a primary standard, but still considered to be of high precision. Secondary standards are often used in industry, research, and other areas where accurate measurements are required, but a primary standard is not practical or cost-effective.
(iv) Working standard: A working standard is a standard that is used in day-to-day operations and is typically less accurate than a secondary standard. It is used to calibrate equipment or instruments that are used in regular operations and it's typically less expensive to use than a secondary standard. A working standard is used to ensure that the equipment is operating correctly and within the acceptable limits of accuracy.
In summary, International standards are agreed upon by a group of countries or international organizations and are used to ensure consistency and compatibility