How to calculate power density easily – Even in your head!
- Convert the diameter to cm,
- Divide the diameter by two to find the radius,
- Use πr^2 to find the area in cm^
- And, finally, divide the laser power by the area to obtain power density.
What is power density measured in?
Power is measured in units of Watts. When we need to express a specific power, we use the unit of Watts per kilogram or W kg − 1 , and when we are dealing with power density, the unit is Watts per volume or W cm − 3 .
How do you calculate power density of light?
Lighting power density is a simple screening measure that indicates whether a space offers opportunities for energy savings. Lighting Power Density (LPD) is defined as watts of lighting per square foot of room floor area (W/sf).
How do you calculate the power density of a wave?
The power density equation has been given as;(i) Q = 1 2 ω ε ′ E 2 ( W / m 3 ) where ε ′ = σ ω , σ is the electric conductivity, ω is the angular frequency and E is the electric field intensity.
What is power density?
Power density is the amount of power (time rate of energy transfer) per unit volume. In energy transformers including batteries, fuel cells, motors, power supply units etc., power density refers to a volume, where it is often called volume power density, expressed as W/m3.
How do you calculate W cm2?
Example: A laser’s output is 4 Watts, and it is illuminating a circle of 3 centimeter diameter. First find the area of the circle, 3.14 x 1.5 x 1.5 = 7 cm2. Then divide the power by the area, 4W / 7cm2 = 0.6 W/cm2.
How do you calculate the power density of an LED?
Calculate the area of a beam using the radius in cm.
How to calculate power density easily – Even in your head!
- Convert the diameter to cm,
- Divide the diameter by two to find the radius,
- Use πr^2 to find the area in cm^
- And, finally, divide the laser power by the area to obtain power density.
What is the power density of LED?
The LED power density is controlled from 0 to 40 mW/cm2, 0–100 mW/cm2, 0–60 mW/cm2 for red, blue, and green LEDs, respectively.
What is the range of power density of LED?
All new LED luminaires are fully dimmable and can be adjusted to suit personal preferences. Occupancy / Vacancy sensors automatically switch off lighting when not required. Reduced lighting power density from 0.93 to 0.20 Watts/ft2.
What is energy density write its formula?
Regarding electromagnetic waves, both magnetic and electric field are equally involved in contributing to energy density. Therefore, the formula of energy density is the sum of the energy density of the electric and magnetic field. Example 1: Find the energy density of a capacitor if its electric field, E = 5 V/m.
What is power density of an antenna?
The power density of an antenna is the measure of power/square cm (in space) from the center of the antenna. The space can be represented as a sphere having a radius “R” (distance from the center of the antenna).
What is power density of battery?
What is Battery Energy Density? Energy density is the measure of how much energy a battery contains in proportion to its weight. This measurement is typically presented in Watt-hours per kilogram (Wh/kg). A watt-hour is a measure of electrical energy that is equivalent to the consumption of one watt for one hour.
How do you calculate power density of a battery?
The energy density of a battery can be simply calculated using this formula: Nominal Battery Voltage (V) x Rated Battery Capacity (Ah) / Battery Weight (kg) = Specific Energy or Energy Density (Wh / kg).
How do you calculate the power density of a laser?
You can get the Energy (J) by dividing Avg. Power (W) of your Laser with its repetition rate. You can then use Energy and Power to calculate Energy Density = Energy (J)/Area(cm2) and Power Density = Power (W)/Area(cm2).
What is mean by high power density?
If a system has a high power density, than it can output large amounts of energy based on its volume.For example, a tiny capacitor may have the same power output as a large battery. Because the capacitor is so much smaller, it has a higher power density.
How do you convert cm2 to W m2?
W/cm2↔W/m2 1 W/cm2 = 10000 W/m2.
What is Watts cm2?
The units for intensity are watts per centimeter squared (W/cm2) or milliwatts per centimeter squared (mW/cm2). Intensity can therefore be thought of as the spatial concentration of power.
How do you convert mW cm2 to MJ cm2?
Light energy at the test material surface is a measure of cumulative intensity exposure (UV light intensity x time), quantified as millijoules/cm2 and is simply: mW/cm2 x seconds = mj/cm.
How do you convert energy density to power density?
Energy density is equal to 1/2*C*V2/weight, where C is the capacitance you computed and V should be your nominal voltage (i.e 2.7 V). Power Density is V2/4/ESR/weight, where ESR is the equivalente series resistance.
What is the formula for power in watts?
The formula for calculating wattage is: W (joules per second) = V (joules per coulomb) x A (coulombs per second) where W is watts, V is volts, and A is amperes of current. In practical terms, wattage is the power produced or used per second. For example, a 60-watt light bulb uses 60 joules per second.
How do you calculate the output power of an LED?
To calculate an LED’s power use, simply multiply the LED’s voltage (in volts) by the LED’s current (in amperes). The result, measured in watts, is the amount of power your LEDs use. For example, if your LED has a voltage of 3.6 and a current of 20 milliamperes, it will use 72 milliwatts of power.
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