Iris diaphragm

Kreis-ausschnitt. m. sector, -bahn, /. circular path orbit, -bewegung,/. circular motion, rotation, revolution, -blende, /. (Photog.) iris diaphragm, -bogen, m. arc of a circle circular arch. 

Adjustable iris diaphragm 11. Barrier-layer type photocell... 

For the examination of wet mounts, the light of the microscope must be properly adjusted. To achieve optimal resolution, the condenser should be centered and focused for Kohler illumination (racked up). To achieve contrast of the objects in the field, light intensity is diminished with the iris diaphragm of the condenser rather than by lowering the condenser. 

Ch - chopper disc, Fhl - filter holder, D - iris diaphragm and interchangeable pinholes of various sizes, Sch - sample chamber, S - sample holder, ID - iris diaphragm, L2 - receiver lens, Ph2 - detector photomultiplier, A - measuring arm, Fh 2 - filter holder, Phi - detector photomultiplier... 

With the preparation on the microscope roughly in focus adjust the substage condenser to focus the iris diaphragm (partially closed), if necessary centering this to the field. 

Ocular Effects. Drug-induced transient myopia has been reported with several sulfonamides. Acetazolamide, an imsubstituted heterocyclic sulfonamide, has also been associated with myopic shifts in refractive error. Shallowing of the anterior chamber is the only variable documented to change in eyes exhibiting this increase in myopia after sulfonamide therapy. Myopia probably results from ciliary body edema that produces a forward displacement of the lens-iris diaphragm. The myopia subsides on reduction or discontinuation of acetazolamide therapy (see Chapter 35). 

Forward rotation of the ciliary body resulting from edema of the ciliary body and/or choroidal effusion, causing a forward displacement of the lens-iris diaphragm... 

The Zeiss-Endter analyzer [87,88] allowed a direct comparison between the projected area of the particle and the area of a reference circle that consisted of a spot of light adjustable in size by an iris diaphragm. The instrument was designed to work with a photomicrograph that could be obtained from an electron microscope to extend the lower size down to around 0.01 pm. Exnor et. al. [89] applied the instrument to size and shape determination of lead powder. A modified instrument, that was rugged and simpler but not as versatile, was described by Becher [90]. 

An optical pyrometer is simply a photometer using monochromatic light (usually. red) in which the intensity of radiation from either a standard or a constant source (electric lamp, oil flame, etc.) is compared with that from the object of which the temperature is desired. Frequently the two intensities are made equal by adjusting various types of absorbing devices (absorption glasses, iris diaphragm, etc.) interposed either on the furnace side or the standard-lamp side of the pyrometer, depending upon... 

Generally the scanning procedure in the fluorescence mode is the same as in the other modes of scanning the chromatogram is scanned by a slit-beam or point-beam. As the intensity of fluorescence of a sample spot is directly proportional to the quantity of the substance of the spot, the entire spot fluorescence can also be measured at one time. For this an iris diaphragm is used, the diameter of which is chosen somewhat wider than the diameter of the spot to be measured 12). 

Figure 7. Thermal lensing experiment. Kr, krypton ion laser Dye, dye laser M, monochromator Gj, G, G3, glass plate A, attenuator S, shutter, L, lens (/ = 200 mm) I, iris diaphragm C, dye cell (path 1 cm) F, interference filter (A = 633 nm) Fj, neutral density filter P, pinhole (diameter d = 1 mm) D Dj, detector HeNe, helium-neon laser.

In all cases when multimode fibres or fibre bundles are used, eare must be taken that the effective NA of the light eones remains eonstant at the input and the output. The most objeetionable design is an iris diaphragm for intensity regulation in front of a fibre. However, the transmission of neutral-density filters, eolour... 

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