May 26, 2015 at 18:45How to compare fixtures and choose the best
I offer an alternative to the traditional scoring system for determining the winner of the competition, for example, fixtures, using the nominations “Lighting device with the best parameters” and “Optimal choice” as an example.
Illustration: the light space in Edward Hopper’s picture “Midnight”
Explanation of the mechanism for the formation of an integral criterion for ranking lighting fixtures using a simplified example:
Let the compared samples have significant numerical characteristics X and Y that vary in comparable proportional ranges.
If the comparison takes into account the characteristics of the high value of X or Y , integral criterion is calculated using the formula K = X + Y .
If the high values of the characteristics X and Y are taken into account , the integral criterion is calculated by the formula K = X⋅Y .
If it is important to high value X and the lowest possible value Y , integral criterion is calculated using the formula K = X / Y .
If a high value of both characteristics is desired, but the characteristic X takes precedence, the integral criterion is calculated by the formula K = X ^ 2⋅Y .
And that’s all! Following a similar logic, George Simon Ohm formulated and recorded a simple pattern - the longer the wire, the less current will pass through it at a given applied voltage. A university education did not stop him from dwelling on the first variable term of the Taylor series, and now the world knows this formula in a minimally measured form as Ohm's law. Humanity not only does not remember the comments on it on 245 pages , but, one might say, did not read it. And if Om formulated the results of his experiments by introducing a complex system of points with weighting coefficients, his portrait would certainly not have been hanged in all school classrooms. We will not complicate and we.
So:
The winner in the nomination “Lighting device with the best parameters” is the lighting device having the maximum value of the integral criterion K1 , calculated by the formula:
where
Φv is the luminous flux in lumens;
W - power consumption in watts;
Φv / W - light output, squared, as it is of primary importance;
Ra is the overall color rendering index;
Kп - ripple factor in percent;
Pf is the power factor;
Tct- the correlated color temperature in degrees Kelvin, rounded to the nearest value from a number of standard in accordance with clause 11.13 of GOST 54350-2011 (if the correlated color temperature of lamps with E27 base and luminaires for indoor lighting of public buildings is less than 4000K, the value 4000K is substituted in the formula If the correlated color temperature of the light of industrial and street lamps is less than 5000K, the value of 5000K is substituted in the formula).
The winner in the “Optimal Choice” nomination is a light device having the maximum value of the integral parameter K2 , calculated by the formula:
where
Φv is the light flux
ք is the cost of the lamp in rubles
Φv/ ք - unit cost of the luminous flux
Comments on the criteria formation logic:
Luminous efficiency when calculating the K1 criteriontaken in the second degree, since the task of the competition is to encourage high-performance lighting devices, take other parameters into account in the second place. We will return the first degree over light output to the formula when the typical value of the efficiency of lighting devices reaches 200 lm / W and does not significantly increase (Theoretical maximum light return of a lighting device with a solar spectrum of D65 in the range 380-780 nm at an efficiency of 100% is 254 lm / W. Achieving a higher luminous efficiency can only be achieved by narrowing the main portion of the spectrum to a maximum of sensitivity of sight at 555 nm.) And the index characterizing the color rendering quality, in that bright future, I believe, we will take in the second degree.
Criterion K2 is obtained from criterion K1by multiplying by the cost of a unit of luminous flux, rather than dividing by cost, since otherwise cheaper lamps or lighting devices with a lower luminous flux would have won. Note that the cost of the luminous flux somewhat depends on the power, but this dependence is not very large and affects the value of criterion K2 less than the spread in the cost of a unit of luminous flux. In addition, the low cost of the light flux is usually accompanied by low efficiency, but this dependence is already compensated in the first approximation when calculating the coefficient K2 .
Illustration: the light space in Edward Hopper’s picture “Midnight”
Explanation of the mechanism for the formation of an integral criterion for ranking lighting fixtures using a simplified example:
Let the compared samples have significant numerical characteristics X and Y that vary in comparable proportional ranges.
If the comparison takes into account the characteristics of the high value of X or Y , integral criterion is calculated using the formula K = X + Y .
If the high values of the characteristics X and Y are taken into account , the integral criterion is calculated by the formula K = X⋅Y .
If it is important to high value X and the lowest possible value Y , integral criterion is calculated using the formula K = X / Y .
If a high value of both characteristics is desired, but the characteristic X takes precedence, the integral criterion is calculated by the formula K = X ^ 2⋅Y .
And that’s all! Following a similar logic, George Simon Ohm formulated and recorded a simple pattern - the longer the wire, the less current will pass through it at a given applied voltage. A university education did not stop him from dwelling on the first variable term of the Taylor series, and now the world knows this formula in a minimally measured form as Ohm's law. Humanity not only does not remember the comments on it on 245 pages , but, one might say, did not read it. And if Om formulated the results of his experiments by introducing a complex system of points with weighting coefficients, his portrait would certainly not have been hanged in all school classrooms. We will not complicate and we.
So:
The winner in the nomination “Lighting device with the best parameters” is the lighting device having the maximum value of the integral criterion K1 , calculated by the formula:
where
Φv is the luminous flux in lumens;
W - power consumption in watts;
Φv / W - light output, squared, as it is of primary importance;
Ra is the overall color rendering index;
Kп - ripple factor in percent;
Pf is the power factor;
Tct- the correlated color temperature in degrees Kelvin, rounded to the nearest value from a number of standard in accordance with clause 11.13 of GOST 54350-2011 (if the correlated color temperature of lamps with E27 base and luminaires for indoor lighting of public buildings is less than 4000K, the value 4000K is substituted in the formula If the correlated color temperature of the light of industrial and street lamps is less than 5000K, the value of 5000K is substituted in the formula).
The winner in the “Optimal Choice” nomination is a light device having the maximum value of the integral parameter K2 , calculated by the formula:
where
Φv is the light flux
ք is the cost of the lamp in rubles
Φv/ ք - unit cost of the luminous flux
Comments on the criteria formation logic:
Luminous efficiency when calculating the K1 criteriontaken in the second degree, since the task of the competition is to encourage high-performance lighting devices, take other parameters into account in the second place. We will return the first degree over light output to the formula when the typical value of the efficiency of lighting devices reaches 200 lm / W and does not significantly increase (Theoretical maximum light return of a lighting device with a solar spectrum of D65 in the range 380-780 nm at an efficiency of 100% is 254 lm / W. Achieving a higher luminous efficiency can only be achieved by narrowing the main portion of the spectrum to a maximum of sensitivity of sight at 555 nm.) And the index characterizing the color rendering quality, in that bright future, I believe, we will take in the second degree.
Criterion K2 is obtained from criterion K1by multiplying by the cost of a unit of luminous flux, rather than dividing by cost, since otherwise cheaper lamps or lighting devices with a lower luminous flux would have won. Note that the cost of the luminous flux somewhat depends on the power, but this dependence is not very large and affects the value of criterion K2 less than the spread in the cost of a unit of luminous flux. In addition, the low cost of the light flux is usually accompanied by low efficiency, but this dependence is already compensated in the first approximation when calculating the coefficient K2 .