Claims Analysis
Total Claims: 9
Claim 1
Independent Claim
162 words
An apparatus for measuring the light permeability of a measuring liquid for the purpose of testing a substance contained therein, comprising a first photoelectric element arranged in a measuring beam emitted by a light source and a second photoelectric element disposed in the path of a comparison beam from the same light source, a differential amplifier having two input terminals with said first photoelectric element being connected to one of said input terminals and said second photoelectric element being connected to the other of said input terminals, an indicator instrument connected to an output terminal of said differential amplifier, and a switch operated electronic regulating system connected to one of said input terminals of said differential amplifier and coming into operation on actuation of said switch for adjusting (1) the voltages set up at the two input terminals of said differential amplifier to the same potential and (2) the voltage applied to said output terminal connected to said indicator instrument to zero.
Claim 2
Independent Claim
162 words
An apparatus for measuring the light permeability of a measuring liquid for the purpose of testing a substance contained therein, comprising a first photoelectric element arranged in a measuring beam emitted by a light source and a second photoelectric element disposed in the path of a comparison beam from the same light source, a differential amplifier having two input terminals with said first photoelectric element being connected to one of said input terminals and said second photoelectric element being connected to the other of said input terminals, an indicator instrument connected to an output terminal of said differential amplifier, and a switch operated electronic regulating system connected to one of said input terminals of said differential amplifier and coming into operation on actuation of said switch for adjusting (1) the voltages set up at the two input terminals of said differential amplifier to the same potential and (2) the voltage applied to said output terminal connected to said indicator instrument to zero.
Claim 3
Dependent Claim
36 words
Apparatus according to claim 1, wherein said regulating system is connected to that input terminal of said differential amplifier which is connected with said second photoelectric element located in the path of said comparison light beam.
Claim 4
Dependent Claim
38 words
Apparatus according to claim 1, wherein said regulating system comprises a differential amplifier which is set up as an integrator, a condenser which feeds the integrated voltage, a Reed contact serving as a switch, and a feed circuit.
Claim 5
Dependent Claim
25 words
Apparatus according to claim 3, wherein the feed circuit maintains the zero-balance for a predetermined period of time after the Reed contact has been reopened.
Claim 6
Dependent Claim
18 words
Apparatus according to claim 3, wherein the feed circuit includes a condenser and an FET (field effect transistor).
Claim 7
Dependent Claim
38 words
Apparatus according to claim 1, wherein the constructional parts are incorporated in a flat elongated casing which can be held in the hand and comprises at least one battery for a lamp which serves as a light source.
Claim 8
Dependent Claim
62 words
Apparatus according to claim 6, wherein the casing of the apparatus has an opening for introduction of a cuvet containing the measuring liquid into the path of the measuring beam, and a wedge filter is movable in the path by a manual operable setting wheel, the knurled periphery of which projects partially at the narrow side of the casing of the apparatus.
Claim 9
Dependent Claim
48 words
Apparatus according to claim 7, wherein a measuring scale is provided on the setting wheel and can be inspected through a viewing window at the flat side of the casing of the apparatus and is adjustable relative to a mark which is fixed in relation to the apparatus.