Luxmeter measures luminous intensity. The SI unit of luminous intensity is candela (cd).
In physics, intensity is a measure of the time-averaged energy flux. The word "intensity" here is not synonymous with "strength", "amplitude", or "level", as it sometimes is in colloquial speech. For example, "the intensity of pressure" is meaningless, since the parameters of those variables do not match.
A lumen is a unit of luminous flux, which is the amount of light emitted per unit time. A watt is a unit of power (such as electrical power), which is the amount of energy consumed per unit time. Light bulbs have ratings in watts, which measures how much electricity they use, and lumens, which measures how much light they give off. For the same kind of bulb (incandescent, fluorescent, LED, etc.), a bulb with a higher wattage will produce more lumens. However, a 10-watt LED or compact fluorescent bulb may produce more lumens than a 40-watt incandescent bulb.
Yes, flux will corrode the bottom of your fire brick forge.
because the flux capacitor allows it to float on air
It will happen in any magnetic field if the iron rod is aligned with the external flux lines and you hammer in the direction of the flux lines, and you have LOTS of patience as you may need to hammer a hundred or more times to get a "strong" magnetization. What happens (if you want to know) is the hammering joggles the magnetic domains from their previous random orientations and they gradually settle into orientations more closely aligned with the external flux lines. The same thing will happen but more effectively if the iron rod is heated to its curie point temperature and then cooled while aligned with the external flux lines. The heat allows all the magnetic domains to realign.
There are two main formulas used to measure light intensity: luminous flux and illuminance. Luminous flux measures the total amount of light emitted by a source, while illuminance measures the amount of light that falls on a surface.
The candela measures luminous intensity, whereas the lumen measures luminous flux. In simple terms, you can think of luminous intensity as being similar to 'brightness', while luminous flux is similar to the rate at which light leaves its source.
A pyranometer is the instrument used for measuring the intensity of sunlight. It measures the total solar radiation flux density in watts per square meter.
Illuminance is another term for luminous-flux density which defines the intensity of the luminous flux arriving at a surface, measured in lumens per square metre, which is given the special name 'lux'.
Luminous flux is measured in lumens (symbol: lm).
Table 1. SI photometry unitsvteQuantity Symbol[nb 1] SI unit Symbol Dimension Notes Luminous energy Qv [nb 2] lumen secondlm⋅s T⋅J [nb 3] units are sometimes called talbots Luminous flux Φv [nb 2] lumen (= cd⋅sr) lm J also called luminous power Luminous intensity Iv candela (= lm/sr) cd J an SI base unit, luminous flux per unit solid angle LuminanceLv candela per square metre cd/m2 L−2⋅J units are sometimes called nitsIlluminanceEv lux (= lm/m2) lxL−2⋅J used for light incident on a surface Luminous emittance Mv lux (= lm/m2) lx L−2⋅J used for light emitted from a surface Luminous exposure Hv lux secondlx⋅s L−2⋅T⋅J Luminous energy density ωv lumen second per metre3 lm⋅⋅m−3 L−3⋅T⋅J Luminous efficacy η [nb 2] lumen per wattlm/WM−1⋅L−2⋅T3⋅J ratio of luminous flux to radiant flux Luminous efficiency V 1 also called luminous coefficient
Not directly, as you are comparing apples with oranges in two senses: (a) a lumen is an SI unit, whereas a candlepower is an Imperial unit, and (b) lumens are used to measure luminous flux, whereas candlepower is used to measure luminous intensity.
Many devices can measure magnetic flux: Hall effect sensors, fluxgates, magnetoresistive devices, etc.
lumen
Intensity of light is measured in units called lux (lx). Lux is defined as the amount of light intensity or luminous flux per unit area. It helps quantify the level of brightness perceived by the human eye.
Candela (cd).
Fluence refers to the total number of particles passing through a unit area, while flux is the rate at which particles pass through a unit area. In radiation measurement, fluence measures the total amount of radiation received, while flux measures the intensity or flow rate of radiation at a specific point.