Quartz Control Plate Calibration Standards

Rudolph Research Analytical Quartz Control Plates provide a permanent calibration standard for polarimeters and saccharimeters. Every Rudolph calibration standard is manufactured using extremely stable crystalline quartz which is mined and polished to specific planeness, parallelism, purity and axis standards.

These standards meet or exceed the specifications outlined on Page 61 of the National Institute for Standards and Technology (NIST) Circular C440 or as laid down by the International Commission for Uniform Methods of Sugar Analysis (ICUMSA). Each Quartz Plate comes complete with a label showing calibration at 8 different wavelengths, a protective box and a NIST Traceable Certificate.

Neither NIST nor ICUMSA provide guidelines for the frequency of Quartz Control Plate Recalibration. Since quartz is optically stable over time, changes in its optical rotation are the result of optical stress or surface scratches caused by physical handling. Therefore, it is the opinion of Rudolph Research Analytical that recalibration of a Quartz Calibration Standard every two to three years is satisfactory.

Selecting a Quartz Plate

Any rotation is available. Quartz Plates come in single and dual versions. Single Quartz Plates - (Figure 1) have a single rotation value at each wavelength and are calibrated in °Arc (Optical Rotation) and °ISS/°Z (Sugar Degrees). Dual Plates are also calibrated in °Arc and °ISS, but have three rotation values at each wavelength (Figure 2). This is possible because each plate is made up of one left or levo turning Quartz Plate (i.e. -28° Arc) and one right or dextro turning plate (i.e. +30° Arc) which may be used separately or together for a combined rotation of 2° Arc (30°-28°). Please contact the factory for the Quartz Plate that is best suited for your needs.