OPTICAL TACHOMETRY FOR MONITORING NMR SAMPLE SPINNING RATES,
Abstract
A simple optical tachometer utilizing fiber optics and solid state electronics has been designed and constructed in order to monitor sample turbine spin speeds on a Varian HA 100D nuclear magnetic resonance spectrometer. By use of a bifurcated fiber optical path, light is transmitted to the turbine strobe, modulated, and returned to the detector within the same plastic-sheathed glass fiber bundle. Rotational information can thus be retrieved without disturbing the magnetic field or sample environment. Employment of this technique may be extended to other applications where conventional tachometry is impractical. With a properly tuned magnet, optimum spectral resolution was observed to be independent of sample spinning rates of 10 to 30 rps. Beyond this rate, the deteriorated resolution was attributed to mechanical noise from precession of an unbalanced sample tube or turbine assembly. (Author)
Document Details
- Document Type
- Technical Report
- Publication Date
- Sep 01, 1969
- Accession Number
- AD0698820
Entities
People
- S. D. Brooks
- T. J. Pratt
Organizations
- Boeing