001/*
002 * Units of Measurement API
003 * Copyright (c) 2014-2021, Jean-Marie Dautelle, Werner Keil, Otavio Santana.
004 *
005 * All rights reserved.
006 *
007 * Redistribution and use in source and binary forms, with or without modification,
008 * are permitted provided that the following conditions are met:
009 *
010 * 1. Redistributions of source code must retain the above copyright notice,
011 *    this list of conditions and the following disclaimer.
012 *
013 * 2. Redistributions in binary form must reproduce the above copyright notice, this list of conditions
014 *    and the following disclaimer in the documentation and/or other materials provided with the distribution.
015 *
016 * 3. Neither the name of JSR-385 nor the names of its contributors may be used to endorse or promote products
017 *    derived from this software without specific prior written permission.
018 *
019 * THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS "AS IS"
020 * AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO,
021 * THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
022 * ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT HOLDER OR CONTRIBUTORS BE LIABLE
023 * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES
024 * (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES;
025 * LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED
026 * AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
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028 * EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
029 */
030package javax.measure.quantity;
031
032import javax.measure.Quantity;
033
034/**
035 * Luminous flux density per solid angle as measured in a given direction relative to the emitting source.
036 * The metric system unit for this quantity is "cd" (candela).
037 *
038 * The candela, symbol cd, is the SI unit of luminous intensity in a given direction. It is
039 * defined by taking the fixed numerical value of the luminous efficacy of
040 * monochromatic radiation of frequency 540 × 10¹² Hz, Kcd, to be 683 when expressed
041 * in the unit lm W−1, which is equal to cd sr W⁻¹, or cd sr kg⁻¹ m⁻² s³, where the kilogram,
042 * metre and second are defined in terms of h, c and ∆νCs.
043 *
044 * This definition implies the exact relation Kcd = 683 cd sr kg⁻¹ m⁻² s³ for monochromatic
045 * radiation of frequency ν = 540 × 10¹² Hz. Inverting this relation gives an exact expression
046 * for the candela in terms of the defining constants Kcd, h and ∆νCs:
047 *
048 * 1 cd = (Kcd / 683) kg m² s⁻³ sr⁻¹
049 * <br>
050 * <dl>
051 * <dt><span class="strong">API Note:</span></dt><dd>SI Base Unit</dd>
052 * </dl>
053 * 
054 * @author <a href="mailto:jean-marie@dautelle.com">Jean-Marie Dautelle</a>
055 * @author <a href="mailto:werner@uom.technology">Werner Keil</a>
056 * @author <a href="mailto:thodoris.bais@gmail.com">Thodoris Bais</a>
057 * @version 2.1
058 * @since 1.0
059 * 
060 * @see <a href="https://en.wikipedia.org/wiki/Luminous_intensity">Wikipedia: Luminous intensity</a>
061 */
062public interface LuminousIntensity extends Quantity<LuminousIntensity> {
063}