Shutter Assembly with Calibration Material

Abstract

A shutter assembly for use with a spectrometer having at least one source of optical radiation such as at least one laser capable of generating an excitation light beam having an illumination path. The shutter assembly includes a shutter having at least one of (i) at least one calibration material capable of generating a consistent spectrum within wavelengths utilizable by the spectrometer and (ii) a mirror capable of diverting at least one of the illumination path and a collection path relative to a calibration standard capable of generating a consistent spectrum within wavelengths utilizable by the spectrometer. The shutter assembly further includes a mechanism capable of moving the shutter into at least a first position in the path of the light beam and a second position out of the path of the light beam to enable a sample to be analyzed.

1 . A shutter assembly for use with a spectrometer having at least one source of optical radiation capable of generating at least one light beam having an illumination path, the shutter assembly comprising:
 a shutter including at least one of (i) at least one calibration material capable of generating a consistent spectrum within wavelengths utilizable by the spectrometer and (ii) a mirror capable of diverting at least one of the illumination path and a collection path relative to a calibration standard capable of generating a consistent spectrum within wavelengths utilizable by the spectrometer; and   a mechanism capable of moving the shutter:   into at least a first position in the illumination path of the light beam such that at least one of (a) the light beam strikes the calibration material as desired yet remains blocked from further travel, (b) the light beam is diverted by the mirror to the calibration standard, and (c) the collection path is diverted by the mirror to communicate with the calibration standard while the illumination path is blocked; and   into a second position out of the illumination path of the light beam to enable a sample to be analyzed.   
     
     
         2 . The shutter assembly of  claim 1  wherein the calibration material is a polymer. 
     
     
         3 . The shutter assembly of  claim 1  wherein the calibration material is polystyrene. 
     
     
         4 . The shutter assembly of  claim 1  wherein the shutter is formed of at least one calibration material. 
     
     
         5 . The shutter assembly of  claim 1  wherein the shutter carries at least two different calibration materials. 
     
     
         6 . The shutter assembly of  claim 1  wherein the calibration material is acetanilide or a derivative thereof. 
     
     
         7 . The shutter assembly of  claim 1  wherein the calibration material is acetaminophen. 
     
     
         8 . The shutter assembly of  claim 1  wherein the mechanism includes a solenoid to move the shutter from the first position to the second position. 
     
     
         9 . The shutter assembly of  claim 1  wherein the mechanism includes a spring for biasing the shutter into the first position. 
     
     
         10 . The shutter assembly of  claim 1  further including a retaining element to encourage the shutter to remain in the first position. 
     
     
         11 . The shutter assembly of  claim 10  wherein the retaining element includes a magnet. 
     
     
         12 . The shutter assembly of  claim 10  wherein the retaining element includes a mechanical detent 
     
     
         13 . A spectrometer capable of performing an internal calibration check comprising:
 at least one source of optical radiation capable of generating at least one excitation light beam with at least one desired spectral feature and having an illumination path;   a shutter including at least one of (i) at least one calibration material capable of generating a consistent spectrum within wavelengths utilizable by the spectrometer and (ii) a mirror capable of diverting at least one of the illumination path and a collection path relative to a calibration standard capable of generating a consistent spectrum within wavelengths utilizable by the spectrometer; and   a mechanism capable of moving the shutter:   into at least a first calibration position in the illumination path of the light beam such that at least one of (a) the light beam strikes the calibration material and is blocked from further travel to a sample measurement site, (b) the light beam is diverted by the mirror to the calibration standard, and (c) the collection path is diverted by the mirror to communicate with the calibration standard while the illumination path is blocked; and   into a second position out of the path of the light beam to enable the light beam to strike a sample at the sample measurement site.   
     
     
         14 . The spectrometer of  claim 13  wherein the source of optical radiation is capable of generating substantially coherent light. 
     
     
         15 . The spectrometer of  claim 14  wherein the light has a wavelength in the range of 700 nanometers to 1100 nanometers. 
     
     
         16 . The spectrometer of  claim 13  wherein the spectrometer is capable of performing Raman spectroscopy. 
     
     
         17 . The spectrometer of  claim 13  wherein the calibration material is a polymer. 
     
     
         18 . The spectrometer of  claim 13  wherein the calibration material is polystyrene. 
     
     
         19 . The spectrometer of  claim 13  wherein the shutter is formed of at least one calibration material. 
     
     
         20 . The spectrometer of  claim 13  wherein the shutter carries at least two different calibration materials, each at a different locus on the shutter, and the mechanism is capable of successively positioning the shutter in different calibration positions, each calibration position corresponding to one of the loci. 
     
     
         21 . The spectrometer of  claim 13  wherein the light beam has a focal length set for the measurement site and, in the first position of the shutter, the light beam strikes the calibration material at a position that is different than the focal length. 
     
     
         22 . The spectrometer of  claim 13  wherein the calibration standard includes a light source with a desired spectral feature. 
     
     
         23 . A method of checking the calibration of a spectrometer capable of generating at least one substantially coherent light beam, comprising:
 selecting a shutter including at least one of (i) at least one calibration material capable of generating a consistent spectrum within wavelengths utilizable by the spectrometer and (ii) a mirror capable of diverting at least one of the illumination path and a collection path relative to a calibration standard capable of generating a consistent spectrum within wavelengths utilizable by the spectrometer;   positioning the shutter into at least a first calibration position in the illumination path of the light beam such that at least one of (a) the light beam strikes the calibration material and is blocked from further travel to a sample measurement site, (b) the light beam is diverted by the mirror to the calibration standard, and (c) the collection path is diverted by the mirror to communicate with the calibration standard while the illumination path is blocked;   analyzing a selected spectrum of light returned from at least one of the calibration material and the calibration standard;   comparing results of the analysis with approved results; and   providing an indication of whether the results of the analysis are within acceptable tolerances.   
     
     
         24 . The method of  claim 23  wherein the light has a wavelength in the range of 700 nanometers to 1100 nanometers. 
     
     
         25 . The method of  claim 23  wherein the spectrometer is capable of performing Raman spectroscopy. 
     
     
         26 . The method of  claim 23  wherein the calibration material is a polymer. 
     
     
         27 . The method of  claim 23  wherein the calibration material is polystyrene. 
     
     
         28 . The method of  claim 23  wherein the shutter is formed of at least one calibration material. 
     
     
         29 . The method of  claim 23  wherein the shutter carries at least two calibration materials, each at a different locus on the shutter, and the shutter is successively positioned in different calibration positions, each calibration position corresponding to one of the loci. 
     
     
         30 . The method of  claim 23  wherein the light beam has a focal length set for the measurement site and, in the first position of the shutter, the light beam strikes at least one of the calibration material and the calibration standard at a position that is different than the focal length. 
     
     
         31 . The method of  claim 23  wherein the calibration standard includes at least one light source. 
     
     
         32 . The method of  claim 23  further including placing a sample in the measurement site and, if the results of the analysis are within acceptable tolerances, moving the shutter into a second position out of the path of the light beam to take a reading of the sample. 
     
     
         33 . A shutter assembly for use with a spectrometer having at least one source of optical radiation capable of generating at least one light beam, the shutter assembly comprising:
 a shutter including at least one calibration material capable of generating a consistent spectrum within wavelengths utilizable by the spectrometer; and   a mechanism capable of moving the shutter into at least a first position in the path of the light beam such that the light beam strikes the calibration material as desired yet remains blocked from further travel, and into a second position out of the path of the light beam to enable a sample to be analyzed.   
     
     
         34 . A method of calibrating a spectrometer capable of generating at least one substantially coherent light beam, comprising:
 selecting a shutter including at least one calibration material capable of generating a consistent spectrum within wavelengths utilizable by the spectrometer;   positioning the shutter in at least a first position in the path of the light beam such that the light beam strikes the calibration material and is blocked from further travel to a sample measurement site;   analyzing a selected spectrum of light returned from the calibration material;   comparing results of the analysis with approved results; and   providing an indication of whether the results of the analysis are within acceptable tolerances.