Illuminance calculator

07 Oct 2024 Tags: Electrical Engineering Illumination Engineering Light and illumination calculation Illumination Calculation Popularity: ⭐⭐⭐Illuminance CalculationThis calculator provides the calculation of illuminance for a given room.ExplanationCalculation Example: Illuminance is a measure of the amount of light that falls on a surface. It is measured in lux (lx). The illuminance at a point is determined by the luminous efficacy of the light source, the wattage of the light source, and the area and height of the room.Q: What is the difference between illuminance and luminous flux?A: Illuminance is a measure of the amount of light that falls on a surface, while luminous flux is a measure of the total amount of light emitted by a light source. Illuminance is measured in lux, while luminous flux is measured in lumens.Q: How does the height of a ceiling affect the illuminance of a room?A: The height of a ceiling affects the illuminance of a room because it changes the distance between the light source and the surface being illuminated. The higher the ceiling, the lower the illuminance.Variables Symbol Name Unit L Room Length m W Room Width m H Ceiling Height m LR Luminous Efficacy lm/W M Wattage W LL Desired Light Level lx Calculation ExpressionRoom Area: The area of the room is given by A = L * W.Room Volume: The volume of the room is given by V = A * H.Illuminance: The illuminance is given by E = (M * LR) / (A * H).CalculatorRoom Length (m): Room Width (m): Ceiling Height (m): Luminous Efficacy (lm/W): Wattage (W): Desired Light Level (lx): Calculated valuesConsidering these as variable values: LL=500.0, LR=100.0, W=4.0, H=3.0, L=6.0, M=100.0, the calculated value(s) are given in table below Derived Variable Value Room Volume 72.0 Room Area 24.0 Illuminance 138.8889 Sensitivity Analysis GraphsRoom Area: The area of the room is given by A = L * W.Impact of null on Room Area TGvar = [-23996.000 TO 24004.000] f(TGvar)=L * TGvar Impact of null on Room Area TGvar = [-23994.000 TO 24006.000] f(TGvar)=TGvar * W Similar Calculators Illuminance Calculations for Lighting Design Illuminance Calculations in Illumination Engineering Calculating Illumination Current Illumination Function Calculators Photographic Light Intensity Calculation Illuminance Calculation in Lighting Design Illumination Fixture Calculation Fixture Wattage Calculation for Illumination Design Illumination Fixture Wattage Calculation Tool Illumination Power CalculationExplore Lighting design Photometry Interior design A room measures 10m x 5m with a height of 3m. Calculate the

Enter the power in watts, luminous efficacy in lumens per watt, surface area in square feet / meters or spherical radius in feet / meters and press the Calculate button to get the illuminance in lux: Lux to watts calculator ► * the predefined luminous efficacy values are typical / average values. Watts to lux calculation formula Watts to lux calculation with area in square feet The illuminance Ev in lux (lx) is equal to 10.76391 times the power P in watts (W), times the luminous efficacy η in lumens per watt (lm/W) divided by the surface area A in square feet (ft2): Ev(lx) = 10.76391 × P(W) × η(lm/W) / A(ft2) Watts to lux calculation with area in square meters The illuminance Ev in lux (lx) is equal to the power P in watts (W), times the luminous efficacy η in lumens per watt (lm/W) divided by the surface area A in square meters (m2): Ev(lx) = P(W) × η(lm/W) / A(m2) Watts to lux calculation ►

To be measured via a light sensor. However, these are usually not calibrated and have strong deviations compared to professional luxmeters. Good to know:Calibrated lux meters should be used to correctly measure illuminance. The measuring head must be aligned parallel to the measuring surface and ideally rest on it. Because the photometer measures all the light incident at this point, care must be taken that the person taking the measurement does not block any luminaire in the measuring field! How can illuminance be calculated? The mean horizontal illuminance Em is calculated from the luminous flux Φ that falls on the observed surface A:illuminance (lx) = luminous flux (lm) / surface A (m2)For practical calculation with a calculator, the illuminance at a point can also be calculated via the luminous intensity. The luminous intensity can be taken from the luminous intensity distribution on the data sheet of the luminaire. The formula to be applied is:illuminance (lx) = luminous intensity (cd) / distance (m)2This formula describes the photometric law of distance: the luminous intensity in candelas (cd) is divided by the square of the distance (m) from the light emission surface to the measuring surface. It is important to note here that the light hits the target surface at right angles. What value must illuminance at the workplace have? Good lighting is important at the workplace in order to concentrate over longer periods, but also to work safely. The European standard EN 12464 specifies the lighting requirements that must be complied with: