(1) In its simplest form, grape sampling might consist of selecting some berries haphazardly from the vineyard and expressing juice into a refractometer to measure sugar content.(2) Discerning the difference between a gas and liquid thus requires a refractometer that can measure slight differences between critical angles and reflection intensities.(3) The refractometer measures the refractive index of the total soluble solids.(4) For most gemstones the refractive index can be measured with a gemmologist's refractometer , but the refractive indices of diamond, some zircons, and certain other gem materials are too high to be measured with most of these instruments.(5) Sucrose in the phloem sap was measured by refractometry .(6) It is common for growers to measure the soluble solid content of fruit using refractometry , as it represents a quick and portable method for the determination of total sugar content under field conditions.(7) In a survey of fruit from thirty-seven temperate-zone species, refractometry was found to substantially overestimate carbohydrate solute concentrations because of the contributions of nonsugar components, particularly lipids.(8) Only the sedimentation equilibrium experiments with the highest loading concentrations were observed with the refractometric Rayleigh optics.(9) According to Moreau-Rio et al., the overall consumer appreciation is related more to the titratable acidity / refractometric index ratio than to the soluble sugars content alone.(10) Preventive maintenance must be performed on all equipment related to the urinalysis including analyzers, pipettors, refrigerators, microscopes and refractometers .
