A Beam Compass by Christoph Trechsler the Elder and the Origin of the Micrometer Screw

1989 ◽  
Vol 24 ◽  
pp. 209-222 ◽  
Author(s):  
Clare Vincent
Keyword(s):  
Micrometer Screw

scholarly journals Modified Method of Krejnin and Murri for the Determination of Absolute Declinations

1990 ◽  
Vol 141 ◽  
pp. 95-95
Author(s):  
S.A. Tolchelnikova-Murri
Keyword(s):  
Equatorial Zone ◽  
Micrometer Screw ◽  
Modified Method ◽  
Scale Error ◽  
Systematic Effects ◽  
Global Reduction ◽  
Improve Planning

Krejnin and Muni's method (1973) enablesenables one to derive absolute declinations of stars in a narrow equatorial zone |δ| < 10′ from observations near the Earth's equator |ϕ| < 10′. Some systematic effects, including the errors of the value of the micrometer screw for two equatorial instruments (or the scale error if one of the instruments is a PZT), might be determined if a global reduction is used for the original observations from the equator and from those of an astrolabe at latitude |ϕ| ∼ 20° to 23°. Astrolabes—especially photoelectric ones (Hu 1988) are considered to be the most efficient for determination of absolute declinations of stars and absolute latitudes of the instruments in Tolchel'nikova-Murri (1985).In Izv. GAO No. 206 the method will be published as well as the criterion for estimating the efficiency of different programs, which is required to improve planning in astrometry.

scholarly journals A telemeter with micrometer screw adjustment

1908 ◽  
Vol s4-26 (156) ◽  
pp. 531-535 ◽  
Author(s):  
F. E. Wright
Keyword(s):  
Micrometer Screw

scholarly journals VIII. On the application of the calculus of probabilities to the results of measures of the position and distance of double stars

1860 ◽  
Vol 10 ◽  
pp. 133-146
Keyword(s):  
Royal Society ◽  
Probable Error ◽  
The State ◽  
Single Measure ◽  
Micrometer Screw ◽  
Double Stars ◽  
Usual Manner ◽  
The Mean

In a communication addressed to the Royal Society “On the results of Periodical Observations of the Positions and Distances of certain Double Stars,” printed in the Philosophical Transactions for 1851, I took occasion to remark that the differences between mean results obtained on different evenings were greater in proportion than those of the separate or partial measures obtained on the same evening, which arise from chance errors of observation, and that this circumstance rendered the application of the Formulæ of the Calculus of Probabilities to the reduction of the observations embarrassing and difficult. In other words, the differences between the mean positions and distances obtained on different nights were greater than would have been anticipated by one who had merely computed the probable error of a single measure in the usual manner from the data furnished by the sums of the squares of the’partial differences from the mean. The observations made since 1851 fully confirm the anomaly in question. It is probable, therefore, that there is some cause which modifies sensibly and in some unknown manner the results obtained. It may be temperature acting on the micrometer screw; it may be the state of the atmosphere or the method of making the observation; but whatever it be, the observations show conclusively that such causes are sometimes in operation.

A comparison of pulsed ultrasound, radiography and micrometer screw gauge in the measurement of skin thickness

1984 ◽  
Vol 9 (2) ◽  
pp. 113-118 ◽  
Author(s):  
J. A. Newton ◽  
J. Whitaker ◽  
S. Sohail ◽  
M. M. R. Young ◽  
S. M. Harding ◽  
...  
Keyword(s):  
Skin Thickness ◽  
Pulsed Ultrasound ◽  
Micrometer Screw
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