Saccharimeter

saccharimeter

[‚sak·ə′rim·əd·ər] (engineering) An instrument for measuring the amount of sugar in a solution, often by determining the change in polarization produced by the solution.

Saccharimeter

a polarization device that determines the sugar content of solutions by measuring the angle of rotation of the plane of polarization of a light beam. The amount of rotation is proportional to the concentration of the solution. Sac-charimeters are used less frequently for measuring concentrations of other optically active substances.

Figure 1. Quartz compensator of a saccharimeter: (1) stationary wedge of dextrorotatory quartz, (2) movable wedge of levorotatory quartz, and (3) auxiliary wedge of glass. The movable quartz wedge is connected to a scale and slides in the directions indicated by the vertical arrow. A zero reading on the scale corresponds to the position of the movable wedge at which the effects of the two quartz wedges are compensated. The glass auxiliary wedge is introduced to prevent a change in direction of the light ray passing through the quartz wedges.

Rotation in a saccharimeter is compensated, that is, the plane of polarization is rotated by an amount equal in magnitude and opposite in direction to the rotation produced by the solution. The compensator in a saccharimeter is a linearly movable quartz wedge (Figure 1) rather than the rotating analyzer of a polarimeter. The dependence of optical activity on the wavelength of the light, that is, the rotatory dispersion, of quartz and sugar are nearly identical. This circumstance allows the solution to be illuminated by white light when a quartz compensator is used in determining the concentration of sugar. The scale along which the compensating wedge travels is calibrated to give a direct reading of the percentage concentration of optically active substance in the solution. Compensation with sac-charimeters, as with polarimeters, involves an equalization of brightnesses of two halves of the field of view. Conditions for measuring sugar content with a saccharimeter have been standardized: the incident white light must first be filtered through a 1.5-cm layer of 6-percent potassium dichromate (K₂Cr₂O₇) solution.

In many modern saccharimeters with polarizational modulation of light, the quartz compensator and scale are connected to a tracking system, and the rotation plane of polarization is compensated automatically.

REFERENCES

Landsberg, G. S. Optika, 4th ed. (Obshchii kurs fiziki, vol. 3.) Moscow, 1957.
Shishlovskii, A. A. Prikladnaia fizicheskaia optika. Moscow, 1961.
Silin, P. M., and N. P. Silina. Khimicheskii kontrol’ sveklosakharnogo proizvodstva, 3rd ed. Moscow, 1960.

单词	saccharimeter
释义	saccharimeter sac·cha·rim·e·ter S0007000 (săk′ə-rĭm′ĭ-tər)n. An instrument, such as polarimeter, that indicates the concentration of sugar in a solution. sac′cha·rim′e·try n. saccharimeter (ˌsækəˈrɪmɪtə) n (Chemistry) any instrument for measuring the strength of sugar solutions, esp a type of polarimeter for determining the concentration from the extent to which the solution rotates the plane of polarized light ˌsacchaˈrimetry n sac•cha•rim•e•ter (ˌsæk əˈrɪm ɪ tər) n. a device for determining the strength of sugar solutions by measuring the rotation of the plane of polarized light they produce. [1870–75] sac`cha•rim′e•try, n. Saccharimeter saccharimeter [‚sak·ə′rim·əd·ər] (engineering) An instrument for measuring the amount of sugar in a solution, often by determining the change in polarization produced by the solution. Saccharimeter a polarization device that determines the sugar content of solutions by measuring the angle of rotation of the plane of polarization of a light beam. The amount of rotation is proportional to the concentration of the solution. Sac-charimeters are used less frequently for measuring concentrations of other optically active substances. Figure 1. Quartz compensator of a saccharimeter: (1) stationary wedge of dextrorotatory quartz, (2) movable wedge of levorotatory quartz, and (3) auxiliary wedge of glass. The movable quartz wedge is connected to a scale and slides in the directions indicated by the vertical arrow. A zero reading on the scale corresponds to the position of the movable wedge at which the effects of the two quartz wedges are compensated. The glass auxiliary wedge is introduced to prevent a change in direction of the light ray passing through the quartz wedges. Rotation in a saccharimeter is compensated, that is, the plane of polarization is rotated by an amount equal in magnitude and opposite in direction to the rotation produced by the solution. The compensator in a saccharimeter is a linearly movable quartz wedge (Figure 1) rather than the rotating analyzer of a polarimeter. The dependence of optical activity on the wavelength of the light, that is, the rotatory dispersion, of quartz and sugar are nearly identical. This circumstance allows the solution to be illuminated by white light when a quartz compensator is used in determining the concentration of sugar. The scale along which the compensating wedge travels is calibrated to give a direct reading of the percentage concentration of optically active substance in the solution. Compensation with sac-charimeters, as with polarimeters, involves an equalization of brightnesses of two halves of the field of view. Conditions for measuring sugar content with a saccharimeter have been standardized: the incident white light must first be filtered through a 1.5-cm layer of 6-percent potassium dichromate (K₂Cr₂O₇) solution. In many modern saccharimeters with polarizational modulation of light, the quartz compensator and scale are connected to a tracking system, and the rotation plane of polarization is compensated automatically. REFERENCES Landsberg, G. S. Optika, 4th ed. (Obshchii kurs fiziki, vol. 3.) Moscow, 1957. Shishlovskii, A. A. Prikladnaia fizicheskaia optika. Moscow, 1961. Silin, P. M., and N. P. Silina. Khimicheskii kontrol’ sveklosakharnogo proizvodstva, 3rd ed. Moscow, 1960. saccharimeter sac·cha·rim·e·ter (sak'ă-rim'ĕ-tĕr), An instrument for determining the amount of sugar in a solution; it may be a polarimeter, a hygrometer, or a container in which the solution is fermented and the amount estimated by the volume of CO₂ produced. Synonym(s): saccharometer [sacchari- + G. metron, measure]
随便看	hop count hopd hopdev hopdm hopdog hope hope+ hope 2000 hope 2 others hope 4 kids international hopea hope academy public charter school hope, acceptance, love, tolerance hope after rape hope against aids hope against (all) hope hope against all hope hope against hope hope against hope, to hope agency for relief and development hope all is well hope and care for little souls hope and homes for children hope and homes for children romania hope and opportunity for postsecondary education act of 1997

saccharimeter

sac·cha·rim·e·ter

saccharimeter

sac•cha•rim•e•ter

Saccharimeter

saccharimeter

Saccharimeter

REFERENCES

saccharimeter

sac·cha·rim·e·ter