EXPLANATORY STATEMENT
Issued by the authority of the Chief Metrologist
National Measurement Act 1960
National Measurement (Recognized-Value Standard of Measurement of the Density of Water) Determination 2026
Purpose and Operation
The purpose of the National Measurement (Recognized-Value Standard of Measurement of the Density of Water) Determination 2026 (the determination) is to legally define the magnitude of the density of water to support legally traceable measurements that depend on the value of that physical quantity.
The position of Chief Metrologist is established, and the functions of the Chief Metrologist identified, in section 18A of the National Measurement Act 1960 (the Act). Subsection 8A(1) of the Act gives the Chief Metrologist the power to determine that magnitudes of physical quantities specified in the determination and magnitudes of physical quantities as ascertained in accordance with a formula set out in the determination shall be recognized-value standards of measurement.
Subsection 8A(4) of the Act provides that a recognized-value standard of measurement is not subject to verification. This means that the magnitude of the physical quantity of the recognized-value standard is deemed to be that which is determined by the Chief Metrologist. A recognized-value standard of measurement is not determined by reference to, comparison with, or derivation from another standard of measurement.
The determination specifies the magnitudes of the density of water specified in Schedule 1 and in accordance with the formulas set out in the determination.
The determination will support applications including, the calibration and certification of volume and flow metering systems and the production of certified reference materials.
The costs associated with incorporating the remade values of density of water into the operations of users of precise legally traceable measurement of density of water are negligible, and form part of the normal cost of maintaining up-to-date capabilities for these stakeholders.
The National Measurement Act 1960 - Determination by the National Standards Commission - Recognized-Value Standard of Measurement of Density - Water, made by the National Standards Commission, dated 21 March 1985 (1985 determination), is repealed in the determination pursuant to subsection 8A(2) of the Act.
Following the creation of the National Measurement Institute in 2004, which incorporated the functions of the National Standards Commission, the 1985 determination continued to remain in force. The magnitudes of the density of water specified in the 1985 determination are maintained and remade in the 2026 determination. The 2026 determination reflects that the National Measurement Institute now carries out the functions that were previously the responsibility of the National Standards Commission, and that it is the Chief Metrologist who is authorised to make the determination.
Further details of the determination are outlined in Attachment A.
Authority
The determination is made by the Chief Metrologist, National Measurement Institute, under paragraphs 8A(1)(a) and (b) of the Act. The determination is a legislative instrument for the purposes of section 8 of the Legislation Act 2003 (Cth).
Consultation
The National Measurement Institute undertook a public consultation from 24 November to 24 December 2025 to inform the remade 2026 determination. The remake does not change the density of water values specified in the 1985 determination. It updates the instrument to reflect that the determination is now made by the National Measurement Institute, through the Chief Metrologist. The consultation was targeted towards stakeholders who currently reference the 1985 determination, including government agencies, measurement laboratories, and industry bodies. Three submissions were received, each of which supported the instrument to be remade.
Statement of Compatibility with Human Rights
A Statement of Compatibility with Human Rights is set out at Attachment B.
Attachment A
Details of the National Measurement (Recognized-Value Standard of Measurement of the Density of Water) Determination 2026
Section 1—Name
This section provides that the name of the determination is the National Measurement (Recognized-Value Standard of Measurement of the Density of Water) Determination 2026.
Section 2—Commencement
This section provides that the determination commences the day after registration.
Section 3—Authority
This section provides that the authority for the making of the determination is paragraphs 8A(1)(a) and (b) of the National Measurement Act 1960 (the Act).
Section 4— Schedules
This section is a machinery provision that gives effect to the provisions in the Schedules to the determination.
Section 5— Definitions
This section sets out the terms referred to in the determination as follows:
Act means the National Measurement Act 1960.
The legislative note makes clear that ‘Recognized-value standard of measurement has the same meaning as in the Act.
Section 6—Recognized-Value Standard of Measurement of the Density of Water
This section sets out how the recognized-value standard of the Density of Water is determined in different scenarios depending on the temperature and mean pressure.
Schedule 1 – The Density of Water in Kilograms per Cubic Metre as a Function of Temperature in Degrees Celsius
This Schedule 1 is a table setting out the density of water in kilograms per cubic metre from 0.0 degrees Celsius to 40 degrees Celsius in 0.1 degrees Celsius increments.
Schedule 2—Repeals
Item 1 repeals the National Measurement Act 1960 - Determination by the National Standards Commission - Recognized-Value Standard of Measurement of the Density of Water (FRLI Ref: F2009B00179).
Attachment B
Statement of Compatibility with Human Rights
Prepared in accordance with Part 3 of the Human Rights (Parliamentary Scrutiny) Act 2011
National Measurement (Recognized-Value Standard of Measurement of the Density of Water) Determination 2026
This Legislative Instrument is compatible with the human rights and freedoms recognised or declared in the international instruments listed in section 3 of the Human Rights (Parliamentary Scrutiny) Act 2011.
Overview of the Legislative Instrument
The National Measurement (Recognized-Value Standard of Measurement of the Density of Water) Determination 2026 supports the national measurement system by formalising the values of the density of water.
Human Rights Implications
This Legislative Instrument does not engage any of the applicable rights or freedoms.
Conclusion
This Legislative Instrument is compatible with human rights as it does not raise any human rights issues.
Dr Victoria Anne Coleman
Chief Metrologist