| oiml.org | International Organization of Legal Metrology |
| nist.gov | National Institute of Standards and Technology (NIST) |
| iso.ch | ISO. International Organization for Standardization |
| isa.org | ISA, the International Society for Measurement and Control |
| inmetro.gov.br | Inmetro - Instituto Nacional de Metrologia, Normalização e |
| ilac.org | ILAC - Home |
| ieee.org | Institute of Electrical and Electronics Engineers |
| iec.ch | International Electrotechnical Commission |
| bipm.fr | Bureau international des poids et mesures |
| astm.org | ASTM International |
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