Up until now, we've been introducing applications in the field of acoustics under the title "Fundamentals of Sound Measurement." Starting now, we'll move away from specific fields and introduce fundamental concepts related to measurement every other month.
The Measurement Act is a law that aims to establish standards for measurement, ensure the proper implementation of measurements, and thereby contribute to economic development and cultural improvement (Article 1 of the Measurement Act). This article defines fundamental concepts for measurement and weighing, so we will introduce some of them here.
It's surprisingly difficult to give a concise explanation when asked, "What is measurement or weighing?" However, the Measurement Act simply defines it as "measuring the quantity of the state of physical objects" (Article 2 of the Measurement Act).
While "quantities of the state of physical objects" can encompass virtually any measurement, the Measurement Law clarifies its scope of application by specifying the following: length, mass, time, electric current, temperature, amount of substance, luminous intensity, angle, solid angle, area, volume, angular velocity, angular acceleration, speed, acceleration, frequency, rotational speed, wavenumber, density, force, moment of force, pressure, stress, viscosity, kinematic viscosity, work, power, mass flow rate, flow rate, heat quantity, thermal conductivity, specific heat capacity, entropy, electric charge, electric field strength, voltage, electromotive force, capacitance, magnetic field strength, magnetomotive force, magnetic flux density, magnetic flux, and inductor. This includes electrical resistance, electrical conductance, impedance, power, reactive power, apparent power, energy, reactive energy, apparent energy, electromagnetic wave attenuation, electromagnetic wave power density, radiant intensity, luminous flux, luminance, illuminance, sound power, sound pressure level, vibration acceleration level, concentration, neutron emission rate, radioactivity, absorbed dose, absorbed dose rate, kerma, kerma rate, irradiation dose, irradiation dose rate, dose equivalent or dose equivalent rate (all of the above as defined in Article 2, Paragraph 1, Item 1 of the Measurement Act), fineness, specific gravity, and other matters specified by Cabinet Order (all of the above as defined in Article 2, Paragraph 1, Item 2 of the Measurement Act).
A "unit of measurement" is defined as "something that serves as a standard for measurement." Regarding units of measurement, those listed in the upper column of Appendix 1, which represent quantities of physical states, are defined to conform to international decisions and practices (Article 3 of the Measurement Law), meaning they should follow the International System of Units (SI). Other units of measurement, as well as units representing multiplication by an integer power of 10, are defined in Articles 4 to 6 of the Measurement Law.
Among the units of measurement, "legal units of measurement" are those specified in Articles 3 to 5 of the Measurement Act. Units other than legal units of measurement are prohibited from being used in trade or certification for quantities of physical states listed in Article 2, Paragraph 1, Item 1 (length, mass, time, electric current, etc.) (Measurement Act, Article 8).
"Transaction" refers to any business activity aimed at providing goods or services, whether for a fee or free of charge. "Certification" refers to publicly or in the course of business declaring to others that certain facts are true (Measurement Act, Article 2, Paragraph 2).
"Measuring instrument" refers to an instrument, machine, or device used for measuring (Article 2, Paragraph 4 of the Measurement Act).
Among measuring instruments, "specified measuring instruments" are those used for measurement in trade or certification, or primarily for use in the daily lives of general consumers, for which standards regarding their structure or error need to be established to ensure proper measurement (Article 2, Paragraph 4 of the Measurement Act). These specified measuring instruments are defined in Article 2 of the Enforcement Order of the Measurement Act, and 18 types are designated, including taxi meters, electricity meters, sound level meters, and vibration meters. Furthermore, when specified measuring instruments are used in trade or certification, their manufacture, repair, inspection, verification, and validity period are also stipulated.
Next time, we will continue to introduce the provisions of the Measurement Law.
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(Excerpt from the email newsletter issued on June 23, 2011)
