Tintometer

L C Thomas and G J Chamberlin (revised by G Shute), Colorimetric Chemical Analytical Methods, 9th edn, Tintometer Ltd, Salisbury, 1970... 

A Handbook of Colorimetric Chemical Analytical Methods, 6th edn, The Tintometer Ltd. 

W.Keyser, "Colorimetric Analysis , Chapman Sc Hall, London (1957) 7)D.F.Boltz, "Colorimetric Determination of Nonmetals , Wiley (1958) 8)E.B.Sandell, "Colorimetric Determination of Traces of Metals , Wiley, NY (1959 ) 9)Tintometer Ltd "Colormetric Chemical Analytical Methods , The Author, Salisbury, England (1959) 10)Vogel, InorgAnalysis (1961) 738-837 (Colorimetric and spectrophotometric analysis description of various colorimeters) ll)Pamphlets and catalogs of A.H.Thomas,... 

Colour.—This is measured, when necessary, with the Lovibond tintometer,8 in which the colour of a layer of solution of definite thickness is compared with that of a series of coloured glasses of definite tints and intensities, these being combined so that they give the same tone and the same intensity of colour as the solution. The colour is then expressed in arbitrary degrees of red, yellow and black. 

Lovibond tintometer—device for measuring the color of a petroleum product, particularly petrolatums. The melted petrolatum is contained in a cell and the color is compared with a series of yellow and red Lovibond glasses. The length of the cell and the color standards that give the best match are reported. See color scale. 

Lovibond tintometer color can also be measured using objective automated instruments. In one version, the intensities of three light beams (red, yellow and white) transmitted by the oil are measured by photoelectric cells, and the results displayed as red and yellow color readings. The white light beam acts as a reference beam, and allows compensation for variation in the intensity of the light source (Rossell, 1986). AOCS Official Method Cc 13j 97 (Firestone, 1998) specifies how an automated tintometer should be used. However, this standard is valid only for refined oils. 

In the United States, the Wesson tintometer method predominates. This subjective method, which is described in AOCS Official Method Cc 13b 45 (Firestone, 1998), is experimentally much the same as the Lovibond method, but uses only red and yellow filters, and specifies the yellow number to be used with any selected red number the method is thus designed to measure the redness of the sample, and is more limited than the Lovibond method. 

Apparatus Use a Lovibond tintometer or the equivalent and a set of color comparison glasses that conform to the AOCS-Wesson Tintometer Color Scale (available from the National Institute of Standards and Technology). A minimum set of glasses consists of... 

Procedure Add 0.1 g of diatomaceous earth to a 60-g sample, agitate for 2.5 min at room temperature (or 10° to 15° above the melting point if the sample is not liquid), and filter. Adjust the temperature to 25° to 35° (or not more than 100 above the melting point), and fill the color tube to the desired mark. Place the tube in the tintometer (in a dark booth or cabinet), and match the sample color as closely as possible with a standard glass. 

Manufactured by The Tintometer Ltd., Milford, Salisbury, England. A similar apparatus is marketed by Hellige, Inc., of Long Island City 1, N.Y. U.S.A., this utilizes Merck s (U.S.A.) indicators. The glass discs in the two instruments are not interchangeable. 

Anonymous, Color Wesson Method Using Color Glasses Calibrated in Accordance with the AOCS-Tintometer Color Scale, AOCS Official Method Ccl3b-45, American Oil Chemists Society, Champaign, Ilhnois, 1997. 

The color of coconut is measured in a Lovibond Tintometer, using a 1-inch or 51 -inch cell for dark and hght colored oils, respectively. Results are given in red and yellow units describing the combination that matches the sample color. Alternatively, the optical density of the oil can be measured with the use of a spectrophotometer in a suitable cell at a wavelength of maximum absorbance. 

Lovibond color (unitless) Determines red/yellow intensity (carotenoids) of oil using Lovibond Tintometer Cc 13e-92... 

The color of the wax will affect the color of the finished product. A Lovibond Tintometer is often used for color measurements, whereby the color of the raw material is compared against a series of colored standard glasses, under a standard light source. The color of the solidified wax of the same sample may be different depending on the amount of occluded air, the rate of cooling, or surface finish. Therefore, the color of many waxes is best measured in the molten state. Two ASTM color standards are used to measure dark-brown to off-white color and off-white to pure white. The refractive index and the specific gravity are other parameters often determined. 

Aromatic amines, and particularly their colored derivatives, were early candidates for industrial instrumental analysis. By the early 20th century the characteristic absorption spectra of synthetic dyes, including those containing amino groups, were available. Spectrophotometers were used in cases where colorimeters and tintometers were of little or no use, such as for examination of solutions containing two or more colorants107. 

Lovibond [Tintometer]. TM for color measurement and water testing equipment used in standard methods specified by ASTM, AOCS, APHA, European and and U.S. Pharmacopoeia, ISO, BA, and IP. 

The bleaching process is used to remove color bodies and other minor impurities. The bleaching adsorbent, usually a clay product, removes residual soap from alkali refining, aldehydes and ketones from decomposed peroxides, and color bodies. The color of bleached oil is widely measured by the Lovibond tintometer color scale. 

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