Micrometer screw

Mikro-lith, m. microlite. -lunker, n. microcavity, micropore, -mechaaik, /. micromechanics, -meterschraube, /. micrometer screw. 

Fig. 1.6. Thin layer cell for in situ IR absorption-desorption measurements based in a model proposed by Seki et al. [32]. WE = working electrode, W = window, L=lead, M = micrometer screw, S = steel spring, SM = simmer gasket.

The necessary thin-layer configuration was obtained by pressing the electrode against the optical window. Different cell constructions have been used. Fig. 1.6 shows a cell similar to one used by Seki et al. [32], The micrometer screw attached to the working electrode allows a reproducible adjustment of electrode-window distances. 

The preparation is then passed under the objective, being kept in focus by means of slight, continuous movements of the micrometer screw this movement is very useful, especially with high magnifications, as it permits the images in different planes to be observed. 

Measurements of sound velocity at ultrasonic frequencies are usually made by an acoustic interferometer. An example of this apparatus11 is shown in Fig. 2. An optically flat piezo-quartz crystal is set into oscillation by an appropriate electrical circuit, which is coupled to an accurate means of measuring electrical power consumption. A reflector, consisting of a bronze piston with an optically flat head parallel to the oscillating face of the quartz, is moved slowly towards or away from the quartz by a micrometer screw. The electrical power consumption shows successive fluctuations as the distance between quartz and reflector varies between positions of resonance and non-resonance of the gas column. Measurement of the distance between resonance positions gives a value for A/2, and if /... 

The horizontal axes of knife and roller were not aligned in the vertical direction instead, the knife touched the roller some millimeters behind the top surface of the roller in order to permit a spring-loaded contact between knife and foil. The contact force is then adjusted by the foil tension. The horizontal, vertical and angular position is adjusted by six micrometer screws. In Figure 4.109, coating has just started and the distinction between the coated and uncoated foil areas is still visible (left). The reservoir with the slurry is shown on the right. 

Ba Micrometer screw buret, Microchemical Specialties, Berkeley, California. 

The spin-flop transition in M11F2 is of first order at ip < -i/y 30 only. Extremely fine orientation of the magnetic field relative to the crystal axis should be achieved (as the permitted error should not exceed several angular minutes). For this reason the solenoid is mounted on a separate plate, and its slope is varied by 4 micrometer screws. 

The experimental arrangements differ according as one or two tubes are employed for forming bubbles. In Jaeger s method1 a single tube is employed, which is adjustable by means of a micrometer screw, so that the depth of its lower end below the liquid is known an accurate know-... 

A useful differential method on this principle has been described by Warren.1 Two equal jets are made, by carefully cutting a fine tube across, and arranged to dip into two beakers containing the solutions whose surface tensions are to be compared the beakers are mounted on stands whose height is accurately adjustable by micrometer screws. Both tubes are connected to the same source of air under measured pressure, and the heights of the beakers are adjusted until the bubbles come alternately from the two tubes. The maximum pressure in the bubbles is then the same, and the surface tensions can be calculated, after ascertaining the depth of the tips of the two tubes below the surface of the liquids, by equation (13) or preferably by a similar equation in which X is substituted for r in (13) and is found from Sugden s tables. 

To observe accurately the position of the beam, a scale micrometer microscope is used. In order to determine the rest point of the balance, the micrometer screw is adjusted until the balance beam is deflecting equally about a fixed point on the scale. Reading the amplitudes is necessary where measurements are carried out in high vacuum (less than 10-5 mm. Hg). For measurements involving an appreciable gas concentration, the system is damped and the beam assumes a stable position within a few minutes. Here the pointer is followed directly on the micrometer screw. 

These micrometer screws are not shown in the figure. The fine adjustment of A2 with... 

The parts shown in fig. 1 were mounted in a cylindrical box with flat top and bottom, that could be evacuated to 10- mm. The top plate carried two glass windows for observation. Leads to the condenser-plates Ci and C2, transmission to the micrometer screws and conductance to the pressure boxes K, vt re all vacuum-tight sealed through the cylinder wall or bottom. The evacuation was necessary to decrease the viscous resistance of the air between the glass plates (see 1.6). 

By manipulating the micrometer screws and the pressure in the pressure-boxes, b can be changed. Due to the steepness of the attractive force stable equilibrium can only be obtained if d is larger than... 

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