Calibration and testing device for optical, single particle, size spectrometers
OwnerRichard K. Jeckinventor
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Abstract
A device comprising a set of fine, uniform, translucent fibers mounted on a suitable holder. When used in conjunction with appropriate neutral density optical filters, if necessary, on suitable particle sizing instruments, the device can easily and quickly be used to perform three important functions--namely, to accurately check the instrument calibration or response to particle size, to locate the limits of the optical depth of field in the particle illuminating beam, and to test the ability of the instrument to detect and register all validly sampled, single particle events.
Claims12
A calibration device for single particle size spectrometers of the type wherein particles to be measured are directed through a sampling chamber to pass transversely through a portion of a collimated light beam, and wherein light scattered or intercepted by the particles is determined by a detector which provides an indication of the sizes and/or number of said measured particles, said calibration device comprising:
- a frame defining an unobstructed opening which is larger than the cross-section of said portion of said light beam;
- at least one translucent fiber having at least one lengthwise section with uniform light scattering properties, said lengthwise section being at least as long as the width of said portion of said light beam;
- and
- means for securing said fiber to said frame such that said lengthwise section of said fiber is extended across at least part of said unobstructed opening;
- wherein said frame is sized to permit it to be moved through the spectrometer sampling chamber while passing said lengthwise fiber section transversely across said portion of said light beam.
A method for calibrating single particle size spectrometers of the type wherein particles to be measured are directed through a sampling chamber transversely through a collimated light beam, and wherein light scattered or intercepted by the measured particles is monitored by a detector which provides an indication of the sizes and/or number of said measured particles, said method comprising the step of:
- passing at least one translucent fiber, having uniform optical characteristics, transversely through said light beam in said sampling chamber in a direction nominally normal to the fiber length while noting the indication provided by said detector.
Dependencies are inferred from the claim text.