| OF | occipitofrontal; open field [test]; optical fundus; orbitofrontal; osmotic fragility; osteitis fibro... |
|---|---|
| OPD | obstetric prediabetic; optical path difference; otopalatodigital [syndrome]; outpatient department; ... |
| OPS | operations; optical position sensor; osteoporosis-pseudolipoma syndrome; outpatient service; outpati... |
| OpScan | optical scanning |
| ORD | optical rotatory dispersion; oral radiation death |
| optical tubelength | <microscopy> The distance from the second principal focal plane of the objective to the front focal plane of the ocular. This distance is about 180 mm for high-power objectives, less for those of low power. (05 Aug 1998) |
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| electron optical axis | <physics> The path of an electron through an electron optical system along which it suffers no deflection due to lens fields. This axis does not necessarily coincide with the mechanical axis of the system. (05 Aug 1998) |
| electron optical system | <apparatus> A combination of parts capable of producing and controlling a beam of electrons to produce an image of an object. (05 Aug 1998) |
| tubelength optical | <microscopy> This distance is measured from the upper focal plane of the objective to the image formed by the objective alone upon removal of the eyepiece. A light microscope so arranged that the specimen, usually a solid-liquid colloid or suspension, is illuminated by a strong pencil of light at right angles to the microscope axis. The visibility is limited by the intensity of the light source. A laser can be used as the source. It is used to detect the presence of light-ultramicroscopic particles within the range of about 0.005,um to 0.2 ~m. Not to be confused with an electron microscope. (05 Aug 1998) |