{"id":"F2026L00240","name":"National Measurement (Recognized-Value Standard of Measurement of the Density of Water) Determination 2026","slug":"national-measurement-recognized-value-standard-of-measurement-of-the-density-of-water-determination-","collection":"legislative_instrument","jurisdiction":"commonwealth","status":"in_force","isInForce":true,"actNumber":null,"makingDate":null,"administeringDepartment":null,"currentVersion":{"id":443187,"registerId":"F2026L00240-fast-fetch-1775958092319","compilationNumber":null,"startDate":"2026-04-12","status":"InForce","reasons":null,"registeredAt":null},"sections":[{"sectionNumber":"1","sectionType":"section","heading":"National Measurement (Recognized-Value Standard of Measurement of the Density of Water) Determination 2026","content":"---\nmeta-content-style-type: text/css\nmeta-content-type: application/xhtml+xml; charset=utf-8\n---\n\n?xml version=\"1.0\" encoding=\"utf-8\" standalone=\"no\"?>\n\n![Commonwealth Coat of Arms of Australia](image.001.jpeg)\n\n \n\nNational Measurement (Recognized-Value Standard of Measurement of the Density of Water) Determination 2026\n\nI, Dr Victoria Anne Coleman, Chief Metrologist, National Measurement Institute, make the following determination.\n\nDated  9 March 2026 \n\n \n\nDr Victoria Anne Coleman\n\nChief Metrologist\n\n \n\n \n\n \n\nContents\n\n1  Name\n\n2  Commencement\n\n3  Authority\n\n4  Schedules\n\n5  Definitions\n\n6  Recognized-Value Standard of Measurement of the Density of Water\n\nSchedule 1— The Density of Water in Kilograms per Cubic Metre as a Function of Temperature in Degrees Celsius\n\nSchedule 2—Repeals\n\n \n\n \n\n1  Name\n\n  This instrument is the National Measurement (Recognized-Value Standard of Measurement of the Density of Water) Determination 2026.\n\n2  Commencement\n\n (1) Each provision of this instrument specified in column 1 of the table commences, or is taken to have commenced, in accordance with column 2 of the table. Any other statement in column 2 has effect according to its terms.\n\n \n\n- Commencement information\n- Column 1 Column 2 Column 3\n- Provisions Commencement Date/Details\n- The whole of this instrument The day after this instrument is registered.\n\n\nNote: This table relates only to the provisions of this instrument as originally made. It will not be amended to deal with any later amendments of this instrument.\n\n (2) Any information in column 3 of the table is not part of this instrument. Information may be inserted in this column, or information in it may be edited, in any published version of this instrument.\n\n3  Authority\n\n  This instrument is made under paragraphs 8A(1)(a) and (b) of the National Measurement Act 1960.\n\n4  Schedules\n\n  Each instrument that is specified in a Schedule to this instrument is amended or repealed as set out in the applicable items in the Schedule concerned, and any other item in a Schedule to this instrument has effect according to its terms.\n\n5  Definitions\n\nNote: Recognized-value standard of measurement is defined in the Act.\n\n  In this instrument:\n\nAct means the National Measurement Act 1960.\n\n6  Recognized-Value Standard of Measurement of the Density of Water\n\n1.     The magnitude of the density of water dt at a temperature t and a mean pressure p, provided t lies within the range 0 °C to 40 °C and p lies within the range 2 × 104 Pa to 106  Pa, is a Recognized-Value Standard of Measurement determined as follows:\n  1.     When p is 101325 Pa and t is one of the temperatures listed in Schedule 1 the magnitude of the density in kg·m-3 is as stated in Schedule 1, which is derived from the following formula:\n\n\n![Start formula d subscript t equals 999.972 minus start fraction open bracket t minus 3.98419 close bracket superscript 2 over 506.60312 end fraction times start fraction open bracket t plus 286.4601 close bracket over open bracket t plus 67.7601 close bracket end fraction end formula](image.002.png)\n\nwhere:\n\ndt is the density in kg m−3\n\nt is the temperature in ℃.\n\n1.     When p is 101325 Pa and t is between two adjacent values of temperature listed in Schedule 1 then the magnitude of the density in kg·m-3 shall be determined from Schedule 1 by linear interpolation.\n2.     When p differs from 101325 Pa the magnitude of the density in kg·m-3 as stated in Schedule 1 or derived in accordance with the above linear interpolation shall be algebraically increased by an amount equal to:\n\n\n![Start formula open bracket 5.0619 minus 0.0309 times t plus 0.0003614 times t superscript 2 close bracket times 10 superscript minus 7 times open bracket p minus 101325 close bracket end formula](image.003.png)\n\n \n\n1.     If the value of t used in Schedule 1 and the above equations does not differ from the true mean temperature of the water by more than 0.1 °C, if the value of p used in the equation does not differ from the true mean pressure within the water by more than 1000 Pa, and if impurities in the water do not exceed 1 part in 105 by mass, the chance is not more than one in one hundred that the density so ascertained differs from the true value of density by more than 0.05 kg·m-3.\n\n\n \n\n\n\n\nSchedule 1— The Density of Water in Kilograms per Cubic Metre as a Function of Temperature in Degrees Celsius\n\n| Temperature (°C) | Density (kg.m-3) | Temperature (°C) | Density (kg.m-3) | Temperature (°C) | Density (kg.m-3) | Temperature (°C) | Density (kg.m-3) |\n| --- | --- | --- | --- | --- | --- | --- | --- |\n| 0.0 | 999.839 | 10.0 | 999.700 | 20.0 | 998.204 | 30.0 | 995.647 |\n| 0.1 | 999.846 | 10.1 | 999.691 | 20.1 | 998.183 | 30.1 | 995.617 |\n| 0.2 | 999.853 | 10.2 | 999.682 | 20.2 | 998.163 | 30.2 | 995.587 |\n| 0.3 | 999.859 | 10.3 | 999.673 | 20.3 | 998.142 | 30.3 | 995.556 |\n| 0.4 | 999.865 | 10.4 | 999.663 | 20.4 | 998.121 | 30.4 | 995.526 |\n| 0.5 | 999.871 | 10.5 | 999.654 | 20.5 | 998.100 | 30.5 | 995.495 |\n| 0.6 | 999.877 | 10.6 | 999.645 | 20.6 | 998.078 | 30.6 | 995.465 |\n| 0.7 | 999.883 | 10.7 | 999.635 | 20.7 | 998.057 | 30.7 | 995.434 |\n| 0.8 | 999.888 | 10.8 | 999.625 | 20.8 | 998.036 | 30.8 | 995.403 |\n| 0.9 | 999.893 | 10.9 | 999.615 | 20.9 | 998.014 | 30.9 | 995.372 |\n| 1.0 | 999.898 | 11.0 | 999.605 | 21.0 | 997.992 | 31.0 | 995.341 |\n| 1.1 | 999.903 | 11.1 | 999.595 | 21.1 | 997.971 | 31.1 | 995.310 |\n| 1.2 | 999.908 | 11.2 | 999.585 | 21.2 | 997.949 | 31.2 | 995.279 |\n| 1.3 | 999.913 | 11.3 | 999.574 | 21.3 | 997.927 | 31.3 | 995.248 |\n| 1.4 | 999.917 | 11.4 | 999.564 | 21.4 | 997.905 | 31.4 | 995.216 |\n| 1.5 | 999.921 | 11.5 | 999.553 | 21.5 | 997.883 | 31.5 | 995.185 |\n| 1.6 | 999.925 | 11.6 | 999.542 | 21.6 | 997.860 | 31.6 | 995.153 |\n| 1.7 | 999.929 | 11.7 | 999.531 | 21.7 | 997.838 | 31.7 | 995.122 |\n| 1.8 | 999.933 | 11.8 | 999.520 | 21.8 | 997.816 | 31.8 | 995.090 |\n| 1.9 | 999.936 | 11.9 | 999.509 | 21.9 | 997.793 | 31.9 | 995.058 |\n| 2.0 | 999.940 | 12.0 | 999.497 | 22.0 | 997.770 | 32.0 | 995.026 |\n| 2.1 | 999.943 | 12.1 | 999.486 | 22.1 | 997.748 | 32.1 | 994.995 |\n| 2.2 | 999.946 | 12.2 | 999.474 | 22.2 | 997.725 | 32.2 | 994.962 |\n| 2.3 | 999.949 | 12.3 | 999.463 | 22.3 | 997.702 | 32.3 | 994.930 |\n| 2.4 | 999.952 | 12.4 | 999.451 | 22.4 | 997.679 | 32.4 | 994.898 |\n| 2.5 | 999.954 | 12.5 | 999.439 | 22.5 | 997.656 | 32.5 | 994.866 |\n| 2.6 | 999.956 | 12.6 | 999.427 | 22.6 | 997.632 | 32.6 | 994.834 |\n| 2.7 | 999.959 | 12.7 | 999.415 | 22.7 | 997.609 | 32.7 | 994.801 |\n| 2.8 | 999.961 | 12.8 | 999.402 | 22.8 | 997.586 | 32.8 | 994.769 |\n| 2.9 | 999.962 | 12.9 | 999.390 | 22.9 | 997.562 | 32.9 | 994.736 |\n| 3.0 | 999.964 | 13.0 | 999.377 | 23.0 | 997.538 | 33.0 | 994.703 |\n| 3.1 | 999.966 | 13.1 | 999.364 | 23.1 | 997.515 | 33.1 | 994.670 |\n| 3.2 | 999.967 | 13.2 | 999.352 | 23.2 | 997.491 | 33.2 | 994.638 |\n| 3.3 | 999.968 | 13.3 | 999.339 | 23.3 | 997.467 | 33.3 | 994.605 |\n| 3.4 | 999.969 | 13.4 | 999.326 | 23.4 | 997.443 | 33.4 | 994.572 |\n| 3.5 | 999.970 | 13.5 | 999.312 | 23.5 | 997.419 | 33.5 | 994.539 |\n| 3.6 | 999.971 | 13.6 | 999.299 | 23.6 | 997.394 | 33.6 | 994.505 |\n| 3.7 | 999.971 | 13.7 | 999.286 | 23.7 | 997.370 | 33.7 | 994.472 |\n| 3.8 | 999.972 | 13.8 | 999.272 | 23.8 | 997.346 | 33.8 | 994.439 |\n| 3.9 | 999.972 | 13.9 | 999.258 | 23.9 | 997.321 | 33.9 | 994.405 |\n| 4.0 | 999.972 | 14.0 | 999.244 | 24.0 | 997.297 | 34.0 | 994.372 |\n| 4.1 | 999.972 | 14.1 | 999.230 | 24.1 | 997.272 | 34.1 | 994.338 |\n| 4.2 | 999.972 | 14.2 | 999.216 | 24.2 | 997.247 | 34.2 | 994.304 |\n| 4.3 | 999.971 | 14.3 | 999.202 | 24.3 | 997.222 | 34.3 | 994.271 |\n| 4.4 | 999.971 | 14.4 | 999.188 | 24.4 | 997.197 | 34.4 | 994.237 |\n| 4.5 | 999.970 | 14.5 | 999.173 | 24.5 | 997.172 | 34.5 | 994.203 |\n| 4.6 | 999.969 | 14.6 | 999.159 | 24.6 | 997.147 | 34.6 | 994.169 |\n| 4.7 | 999.968 | 14.7 | 999.144 | 24.7 | 997.121 | 34.7 | 994.135 |\n| 4.8 | 999.967 | 14.8 | 999.130 | 24.8 | 997.096 | 34.8 | 994.101 |\n| 4.9 | 999.965 | 14.9 | 999.115 | 24.9 | 997.071 | 34.9 | 994.066 |\n| 5.0 | 999.964 | 15.0 | 999.100 | 25.0 | 997.045 | 35.0 | 994.032 |\n| 5.1 | 999.962 | 15.1 | 999.084 | 25.1 | 997.019 | 35.1 | 993.998 |\n| 5.2 | 999.960 | 15.2 | 999.069 | 25.2 | 996.993 | 35.2 | 993.963 |\n| 5.3 | 999.958 | 15.3 | 999.054 | 25.3 | 996.968 | 35.3 | 993.929 |\n| 5.4 | 999.956 | 15.4 | 999.038 | 25.4 | 996.942 | 35.4 | 993.894 |\n| 5.5 | 999.954 | 15.5 | 999.023 | 25.5 | 996.916 | 35.5 | 993.859 |\n| 5.6 | 999.952 | 15.6 | 999.007 | 25.6 | 996.889 | 35.6 | 993.824 |\n| 5.7 | 999.949 | 15.7 | 998.991 | 25.7 | 996.863 | 35.7 | 993.790 |\n| 5.8 | 999.946 | 15.8 | 998.975 | 25.8 | 996.837 | 35.8 | 993.755 |\n| 5.9 | 999.943 | 15.9 | 998.959 | 25.9 | 996.810 | 35.9 | 993.719 |\n| 6.0 | 999.940 | 16.0 | 998.943 | 26.0 | 996.784 | 36.0 | 993.684 |\n| 6.1 | 999.937 | 16.1 | 998.927 | 26.1 | 996.757 | 36.1 | 993.649 |\n| 6.2 | 999.934 | 16.2 | 998.910 | 26.2 | 996.730 | 36.2 | 993.614 |\n| 6.3 | 999.930 | 16.3 | 998.894 | 26.3 | 996.704 | 36.3 | 993.578 |\n| 6.4 | 999.927 | 16.4 | 998.877 | 26.4 | 996.677 | 36.4 | 993.543 |\n| 6.5 | 999.923 | 16.5 | 998.860 | 26.5 | 996.650 | 36.5 | 993.508 |\n| 6.6 | 999.919 | 16.6 | 998.843 | 26.6 | 996.623 | 36.6 | 993.472 |\n| 6.7 | 999.915 | 16.7 | 998.827 | 26.7 | 996.595 | 36.7 | 993.436 |\n| 6.8 | 999.910 | 16.8 | 998.809 | 26.8 | 996.568 | 36.8 | 993.400 |\n| 6.9 | 999.906 | 16.9 | 998.792 | 26.9 | 996.541 | 36.9 | 993.365 |\n| 7.0 | 999.902 | 17.0 | 998.775 | 27.0 | 996.513 | 37.0 | 993.329 |\n| 7.1 | 999.897 | 17.1 | 998.757 | 27.1 | 996.486 | 37.1 | 993.293 |\n| 7.2 | 999.892 | 17.2 | 998.740 | 27.2 | 996.458 | 37.2 | 993.257 |\n| 7.3 | 999.887 | 17.3 | 998.722 | 27.3 | 996.430 | 37.3 | 993.221 |\n| 7.4 | 999.882 | 17.4 | 998.704 | 27.4 | 996.403 | 37.4 | 993.184 |\n| 7.5 | 999.877 | 17.5 | 998.687 | 27.5 | 996.375 | 37.5 | 993.148 |\n| 7.6 | 999.871 | 17.6 | 998.669 | 27.6 | 996.347 | 37.6 | 993.112 |\n| 7.7 | 999.866 | 17.7 | 998.650 | 27.7 | 996.318 | 37.7 | 993.075 |\n| 7.8 | 999.860 | 17.8 | 998.632 | 27.8 | 996.290 | 37.8 | 993.039 |\n| 7.9 | 999.854 | 17.9 | 998.614 | 27.9 | 996.262 | 37.9 | 993.002 |\n| 8.0 | 999.848 | 18.0 | 998.596 | 28.0 | 996.234 | 38.0 | 992.965 |\n| 8.1 | 999.842 | 18.1 | 998.577 | 28.1 | 996.205 | 38.1 | 992.929 |\n| 8.2 | 999.836 | 18.2 | 998.558 | 28.2 | 996.177 | 38.2 | 992.892 |\n| 8.3 | 999.830 | 18.3 | 998.540 | 28.3 | 996.148 | 38.3 | 992.855 |\n| 8.4 | 999.823 | 18.4 | 998.521 | 28.4 | 996.119 | 38.4 | 992.818 |\n| 8.5 | 999.816 | 18.5 | 998.502 | 28.5 | 996.090 | 38.5 | 992.781 |\n| 8.6 | 999.810 | 18.6 | 998.483 | 28.6 | 996.062 | 38.6 | 992.743 |\n| 8.7 | 999.803 | 18.7 | 998.463 | 28.7 | 996.033 | 38.7 | 992.706 |\n| 8.8 | 999.795 | 18.8 | 998.444 | 28.8 | 996.003 | 38.8 | 992.669 |\n| 8.9 | 999.788 | 18.9 | 998.425 | 28.9 | 995.974 | 38.9 | 992.632 |\n| 9.0 | 999.781 | 19.0 | 998.405 | 29.0 | 995.945 | 39.0 | 992.594 |\n| 9.1 | 999.773 | 19.1 | 998.386 | 29.1 | 995.916 | 39.1 | 992.557 |\n| 9.2 | 999.766 | 19.2 | 998.366 | 29.2 | 995.886 | 39.2 | 992.519 |\n| 9.3 | 999.758 | 19.3 | 998.346 | 29.3 | 995.857 | 39.3 | 992.481 |\n| 9.4 | 999.750 | 19.4 | 998.326 | 29.4 | 995.827 | 39.4 | 992.444 |\n| 9.5 | 999.742 | 19.5 | 998.306 | 29.5 | 995.797 | 39.5 | 992.406 |\n| 9.6 | 999.734 | 19.6 | 998.286 | 29.6 | 995.768 | 39.6 | 992.368 |\n| 9.7 | 999.725 | 19.7 | 998.266 | 29.7 | 995.738 | 39.7 | 992.330 |\n| 9.8 | 999.717 | 19.8 | 998.245 | 29.8 | 995.708 | 39.8 | 992.292 |\n| 9.9 | 999.708 | 19.9 | 998.225 | 29.9 | 995.678 | 39.9 | 992.254 |\n| 10.0 | 999.700 | 20.0 | 998.204 | 30.0 | 995.647 | 40.0 | 992.215 |\n\n\n \n\n \n\n\n\n\nSchedule 2—Repeals\n\nNational Measurement Act 1960 - Determination by the National Standards Commission - Recognized-Value Standard of Measurement of Density – Water\n\n1  The whole of the instrument\n\nRepeal the instrument\n\n \n\n \n","sortOrder":0}],"analysis":{"flash_summary_failed":{"failed":true,"reason":"Unauthenticated. Configure AI_GATEWAY_API_KEY or use a provider module. Learn more: https://ai-sdk.dev/unauthenticated-ai-gateway","source":"analysis-cron"},"kimi_summary":{"content_quality":"ok","complexity_score":3,"scope_assessment":{"changed":false,"description":"The legislation maintains its original narrow technical purpose: establishing a recognized-value standard for water density measurement. It replaces an older equivalent standard with updated scientific values but does not expand beyond this specific metrological function."},"complexity_factors":["Only 2 defined terms in the interpretation section ('Act' and reference to 'Recognized-value standard of measurement' defined externally)","Single operative provision (section 6) with clear sequential logic (standard pressure table → interpolation → pressure correction → uncertainty statement)","No nested exceptions or conditional cross-references to other legislation beyond the parent Act","Mathematical formulas are complex but presented as self-contained equations rather than legislative conditional logic","Schedule 1 is a large data table (401 data points) but is purely reference material, not operational complexity","Straightforward repeal mechanism in Schedule 2 replacing a single predecessor instrument"],"plain_english_summary":"This law establishes Australia’s legally recognised standard for water density, providing a formula and a 0–40°C lookup table (0.1°C steps) plus a pressure-correction method. It sets reference pressure and uncertainty limits and repeals the outdated 1960s standard.\n\nIt affects laboratories, calibration services, industries and researchers that require traceable, consistent water-density values for compliance, trade and precision measurements."},"flash_summary":{"complexity_score":3,"scope_assessment":{"changed":true,"description":"This instrument repeals the earlier Determination (Schedule 2) and replaces the recognized‑value standard for water density with the values, formulas and procedural rules set out in s.6 and Schedule 1. It therefore alters the operative instrument in force and sets explicit temperature (0–40 °C) and pressure (2×10^4–10^6 Pa) ranges and the specific interpolation, correction and uncertainty conditions that users must follow."},"complexity_factors":["Technical metrology content (numerical table of density values for each 0.1 °C from 0.0–40.0 °C) — Schedule 1.","Analytical formula used to derive table values at standard pressure (101325 Pa) — s.6(1)(a).","Linear interpolation requirement for temperatures between listed values — s.6(1)(b).","Pressure‑correction algebraic expression for non‑standard pressures (p ≠ 101325 Pa) and defined valid pressure range 2×10^4 Pa to 10^6 Pa — s.6(1)(c).","Uncertainty and validity conditions: temperature accuracy ±0.1 °C, pressure accuracy ±1000 Pa, impurity limit 1×10−5 by mass, probability/statistical statement of 0.05 kg·m−3 at 1% risk — s.6(2)/(3).","Legal machinery (commencement, authority under National Measurement Act 1960, and repeal of prior instrument) increases administrative steps but not technical complexity — ss.2–4; Schedule 2."],"plain_english_summary":"This Determination sets the official standard values and procedure for measuring the density of water. It provides a table of densities for 0–40 °C at 101325 Pa, a generating formula, a rule to linearly interpolate between table entries, and a pressure‑correction formula for pressures from 2×10^4 Pa to 10^6 Pa. It applies to laboratories, calibration services, regulators and businesses that rely on traceable density values for measurement, testing or legal metrology and replaces the earlier Determination."}},"importantCases":[],"_links":{"self":"/api/acts/national-measurement-recognized-value-standard-of-measurement-of-the-density-of-water-determination-","history":"/api/acts/national-measurement-recognized-value-standard-of-measurement-of-the-density-of-water-determination-/history","analysis":"/api/acts/national-measurement-recognized-value-standard-of-measurement-of-the-density-of-water-determination-/analysis","conflicts":"/api/acts/national-measurement-recognized-value-standard-of-measurement-of-the-density-of-water-determination-/conflicts","importantCases":"/api/acts/national-measurement-recognized-value-standard-of-measurement-of-the-density-of-water-determination-/important-cases","documents":"/api/acts/national-measurement-recognized-value-standard-of-measurement-of-the-density-of-water-determination-/documents"}}