R axis 360 degree rotation stage
R axis 360 degree rotation stage lapsaipc PT- R38/R60/R80/R100/R125 R Axis Manual Rotary Stage Rotation Stage Rotating Platform 360 degree rotary table
Quality Control: Every parts tested with special instruments or main boards before delivery to ensure working.
All Tablet/ Phone Spare Parts Packed in anti-static bags, then put in a bubble bag or a small box to ensure safety in transportation.
Characterization of a self-calibrating, high-precision
We present R axis 360 degree rotation stage details on the alignment and calibration of a goniometer assembly consisting two stacked, optically encoded, vertical axis rotation stages. A technique for its calibration is presented that utilizes a stable, uncalibrated, third stage to position a mirror in conjunction with a nulling autocollimator.
Such a system provides a self-calibrating set of angular stages with absolute accuracy of ±0.1 second of plane angle (k=2 expanded uncertainty) around the full circle, suitable for laboratory application. This calibration technique permits in situ, absolute angular calibration of an operational goniometer assembly that is requisite for fully traceable angle measurement, as the installation of the encoder is known to change its performance from the angular calibration data provided by the manufacturer.
The National Institute of Standards and Technology provides a suite of Standard Reference Materials (SRMs) for calibration of diffraction measurements and equipment. While powder diffraction can provide information on a multitude of sample characteristics, the ubiquitous measurement issue is that of diffraction line position.
This corresponds to the measurement of the crystallographic lattice parameters in a manner that is traceable to the Système Internationale (SI) via Bragg’s law: λ = 2d sinθ. Bragg’s law relates the wavelength of the X-rays used in the experiment, λ, to the hkl lattice spacing, d, of the sample; the sample may be either in the form of a powder or a single crystal. In order to establish SI traceability, the lattice spacing of well characterized reference crystals is established via X-ray / Optical interferometry [1, 2].
These crystals are used in a double crystal diffraction experiment to yield an SI traceable characterization of the x-ray emission spectrum of a given element. Lastly, the powder sample is characterized using the known spectrum, yielding the desired SRM certified with respect to lattice parameters.
Both the characterization of the R axis 360 degree rotation stage emission spectrum and the powder measurements require a dual, concentric axes goniometer for which a self calibrating angle measurement verification procedure has been conducted. Therefore; a procedure for calibration of a goniometer assembly suitable for use in laboratory setting, with a minimum impact on it’s angular measurement application, is needed.
Laboratory goniometers typically utilize a worm and ring gear arrangement to achieve the rotational motion, with an optical encoder to measure the rotation angle. The use of optical encoders to provide absolute angular calibration of goniometer stages is well established.
There is a long history of calibrating such stages by methods known either as “circle closure” or “cross calibration”. The highest precision stage yet realized, described in, is a purpose-built angular calibration system, and not suitable in our application. Optical encoders are typically provided with specifications of their angular accuracy, as measured by the manufacturer under reasonable conditions.
This accuracy is typically guaranteed only if the encoder is installed correctly, but this statement is essentially circular; if it doesn’t meet specifications, it is probably installed incorrectly. Therefore, one must have an independent in situ method to demonstrate the accuracy of the measurement.
Furthermore, it is well known that the manufacturer’s specifications for the accuracy of the encoder are worst-case bounds on long-period periodic errors which we show to be temporally stable; therefore, quantification of these long-range errors will yield an angle measurement accuracy superior to the manufacturer’s original specifications.
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