use photometers in a sentence.
Just a barely perceptible change in brightness, but observers interested in DSLR or photoelectric photometers may want to use this project as an entry point.
Of all the photometers which have been devised for that purpose we do not know any one more practical than that suggested in 1876 by Mr.J. Loeffler, of Staten Island.
Even when allowance is made for the difficulties in determining illuminating power, especially when different photometers, different standards of light, and different observers are concerned, it will be seen that these results are too irregular to be altogether trustworthy, and that much more work must be done on this subject before the economy of the acetylene flame can be appraised with exactitude.
Density can never be exactly learned; but strange to say, photometers measure the quantity of light that any bright body emits; hence the stars cannot have specific gravity very far different from that of the sun, since they send similar light, and in quantity obeying the law wherein light varies inversely as the squares of distance.
We are the photometers, we the irritable goldleaf and tinfoil that measure the accumulations of the subtle element.