What is a photometer and how does it work?

Answer 1

Flame photometers work by separating the chemical sample into a constituent atoms and molecules. Then colors are emitted do to the chemicals as they absorb then release energy.

Answer 2

White light from light source is directed to monochromator that selects a single wavelength, or color, of the light to strike the cuvette.

It is the incident light and represents 100 % of the light striking the cuvette (Absorbs by the sample). It is the transmitted light. This is the remaining light which has not been absorbed by the solution in the cuvette and will strike the phototube or detector. The photons of light which do strike the phototube will be converted into electrical energy. This current which has been produced is very small and must be amplified before it can be efficiently detected by the galvanometer. The deflection of the needle on the galvanometer is proportional to the amount of light which originally struck the phototube and is thus an accurate measurement of the amount of light which has passed through (been transmitted by) the sample.

Answer 3

Light brightness is measured with a device called a photometer. Direct reading photometers are often expensive and difficult to use. However, if we
only need to know when two light sources are showing the same brightness, we can create a fairly
simple differential photometer. And, though simple, the results from our differential photometer can
be remarkably sophisticated. By applying our knowledge of how light becomes fainter with distance, we
will combine the differential photometer with meter sticks to measure the intrinsic brightness of lights
and candles with good precision.
The differential photometer consists of two wax blocks and a piece of aluminum foil located
between the wax blocks. When viewed from the edge, this photometer will allow you to judge when the
two wax blocks are equally bright. Then, if we measure the distances to the light sources located to the
left and right of the blocks , we can calculate their brightness ratios. If the brightness of
one light source is known, we can instead calculate the brightness of the other light source.
At this station, you will use your photometer to verify the brightness-distance relation you found
in Station 1. You will also use your photometer to measure the brightness of a light bulb of unknown
power as well as a candle. You will get more consistent results if the light sources you are comparing
are kept at the same height. See diagram of bulb stands


Luminosity of the Sun
We can combine our new understanding of how light becomes fainter for larger distances with
use of the differential photometer to measure directly the luminosity of the Sun. On a sunny day, take
one 200 W light bulb, a meter stick, and your differential photometer outside. Set up the bulb,
photometer, and meter stick as shown in Figure 3. Move the photometer until is shows equal brightness
from the distant Sun and the nearby light bulb. Perform the necessary calculations to determine the
Sun's luminosity.
credit:http://people.bu.edu

Answer 4

Light meters, ,more properly Photometers- and photo in both senses- light and Photography, are highly useful devices. they combine the functions of a circular slide-rule and an analog light meter proper. The selenium types use photoelectric cells of the direct, or photo-voltaic type- these generate electricity in response to available light ( do not require external batteries_ the Cadmiums Sulfide- or CDS light meters merely change the resistance when light hits them and do require outside current to function- small batteries- but they can fail. As there are some environmental hazards regarding selenium- other elements- which are useful for photoelectric cells- have been pressed into service including Silicon. One sets up the meter by dialing the small movable dial to the ASA ( American Standards AssN) film speed value- say 400. this is usually at the south end of the case Okay one points the meter towards the target area and reads off in EV ( Exposure values) One turns the outer dial to line up with the needle of the photoelectric meter ( which is brought down with a varied movement of magnets, watch-like mainsprings, and electrical shunts) and then matches this with the shutter speed and F ( focal plane- Okay Focus) stops. So one gets an exposure value of say 60 ( l/60 second) at F 5.6 this is good for an indoor evening exposure available light. ( yes there are separate sections, scales and even meters for Flash use- I needn"t get into this in an introductory lesson on Photometers! The design of these things is intriguing and the electronic and mechanical ( like most old-style instruments is really cool. I advise you to buy one and experiment! It is a survival of the slide-rule principle in the Round, which is unusual, plus the photocell and mechanical link. Oh, and do cover the photocell and/or switch off when not in use, store in dark space.

Answer 5

Flame photometers work by separating the chemical sample into a constituent atoms and molecules. Then colors are emitted do to the chemicals as they absorb then release energy.

Answer 6

hey simple. just ask someone who knows