Brightness unit: in what is measured today and what are outdated units
It is currently known, that in this world everything can be measured, everything. The universe and much more, surrounding a person, related to measurements. So, measure speed, time, the distance will not be particularly difficult. There are special devices for measurements. Science, which deals with measurements is metrology. Metrology calculates all information with extreme accuracy. It is important to know, in which units something concrete is measured. Example, man knows for sure, that time can be measured in seconds, hours and even milliseconds. Speed can be measured in kilometers per hour, distance in meters or kilometers.
Units of measurement are usually present in physics. Physics helps to learn about measurements from school. With the help of this science, you can translate any measurement into the SI system.
The importance of physics is very great, it has been used at all times. Even brightness can be measured with units. Science is advancing, opens new horizons, it does not stand still and develops. There are units of measurement, which are obsolete today:
- NO,
- stilb,
- Lambert,
- APOSTILE.
Values of brightness units
- NIT is an outdated unit, previously it was used in the SI system, its dimension is approximately 1KD / 1 m? . Now the standards of this unit have not been used for a long time and have been replaced by completely new ones.
- Stilb - used in the GHS system. The brightness of the glowing surface area 1 cm 2 is 1 stilb. It is also practically obsolete, and is not used by modern humanity.
- Lambert is an off-system unit of brightness, began to be used for the first time in the United States. This unit was named after Lambert Johann Heinrich. German mathematician, astronomer, physicist and philosopher, the scientist was of French origin. Abbreviated lambert write, as lb.
- APOSTILB - unit of measurement for illuminated surfaces is also used in the GHS system. It was discovered by French physicist Andre Blodel. APOSTILE with 1978 year is officially considered obsolete and is no longer used.
Where this knowledge may be needed
Many people like to guess crosswords and scanwords. Authors, who invent scanwords, use a kind of terminology and increasingly want to confuse the reader. It is necessary to try, to guess the exact answer. You think, which may require knowledge of the unit of brightness? Scanword may well contain a similar question.
Example, such a case. You need to solve word for word from scanwords: Excellent. To make it easier to decipher the word, there is a hint - this is the unit of brightness of the luminous surface, the word itself consists of 3 letters. These tips are easy to identify, what a word. The answer to the scanword: NO.
Modern unit of brightness
Science, which studies light processes, called photometry. It characterizes the electromagnetic radiation of the light range. In photometry, measurements are performed using the spectrum range, which does not differ from the review of the visibility of the human eye. Brightness determines the flux, which is sent only in a certain direction of the visible surface, it may well characterize the glowing body.
In the international system of measurements (SI) brightness can be measured in candelas per square meter. If earlier the measurement of brightness was NIT, now it is customary to measure it in candelas.
Candela per square meter (cd / m?) - is a derivative of brightness in the SI system, based on two dimensions: light power and square meter.
Depending on that, to what extent it is necessary to measure the brightness of surfaces, there are such measurements, as a candela per square centimeter, candela per square foot, candela per square inch and even kilocandela per square meter.
Kilokandela per square meter (KKD / m?) - is also a measure of brightness, but unlike ordinary candela, it is a multiple of the derivative in the SI system.
The modern world has come so far, that progress is reaching new heights. So, a special converter has appeared, with which you can convert absolutely any brightness unit to any other. This will not be particularly difficult, it is enough to write a unit of measurement, which needs to be translated, and get the right answer. The correct answer may not always be extremely accurate, and with some errors, because sometimes converters can only round to 10 digits after the comma. Some converters may shorten to exponential recording, example: 1,103E +6. E is an exponent, which in mathematics is easy to translate, multiplied by ten to the power.
