[Taxon]: NRC CMC Photometry & Radiometry

[ryanmwhitephd]

Contact Details

No response

What is the process type?

None

Measurand

Wavelength Wavenumber Color temperature, correlated Absorbance, regular, spectral Radiance factor, spectral Radiance factor, total (reflected plus luminance), spectral Whiteness Radiance, spectral Reflectance, diffuse, spectral Reflectance, regular, spectral Reflectance, hemispherical, spectral Illuminance Responsivity, spectral, power Irradiance, spectral

Kind of quantity

Wavelength Wavenumber Color temperature Absorbance Radiance factor Whiteness Radiance Reflectance Illuminance Responsivity Irradiance

Does the measurand require a special token?

None

Taxon Name

No response

[ryanmwhitephd]

CMCs exist for Reflectance and Reflectance factor. Currently, we've defined: Measure.Ratio.RadiantFlux.Reflectance.Specular | Radiometry | Regular reflectance factor Measure.Ratio.RadiantFlux.Reflectance.Diffuse | Radiometry | Diffuse reflectance factor

Reflectance factor refers to a perfect reflecting diffuser, see https://cie.co.at/eilvterm/17-24-070.

[ryanmwhitephd]

Responsivity, spectral, power refers to the response of a (broad band) detector given monochromatic source. Source.Ratio.Power.Spectral?

[ryanmwhitephd]

Measure.Ratio.LuminousFlux is not a ratio, flux is a change in a quantity per unit time. Luminous flux is measured in lumens.

Should this be Measure.LuminousFlux?

[ryanmwhitephd]

Parameters already suggested. Wavelength Incidence angle View angle (detector angle) Sample size Polarization

Some others discussed Bandwidth Aperture type or size Distance (in additional to angle, there is a distance from source the detector is positioned) Diffuse rather than view angle

As a start, NRC will identify a measurand that is complex, another which is straightforward.

[ryanmwhitephd]

Suggested measurement quantities to specify measurand taxons:

• Luminous Flux 17-21-039 e-ILV vocabulary Change in luminous energy with time, and is expressed in lumen (lm).

• Luminous Intensity 17-21-045 e-ILV vocabulary Density of luminous flux with respect to a solid angle in a specified direction, and is expressed in candela (lm sr-1).

• Spectral irradiance 17-21-056 e-ILV vocabulary Density of irradiance with respect to wavelength, and is expressed in watt per square meter per nanometer (W m-2 nm-1)

[ryanmwhitephd]

Measure.LuminousIntensity Type of lamp - Incandescent or LED Output range - Range of luminous intensities that capability covers (Range of candela) Direction with respect to a feature of device Solid angle (angular variation with respect to that direction) Operating conditions of lamp (specific by client) - driving voltage or current; depends on the device.

Report direction and solid angle. Wavelength spectrum is already defined (optical spectrum) In terms of standards, typically measure DC. Sometimes AC (additional parameters may be needed).

[ryanmwhitephd]

https://www.astro.uvic.ca/~tatum/stellatm/atm1.pdf

While aimed at astronomers, may be a useful reference for this exercise.