Color numbers

Methanol can be converted to a dye after oxidation to formaldehyde and subsequent reaction with chromatropic acid [148-25-4]. The dye formed can be deterruined photometrically. However, gc methods are more convenient. Ammonium formate [540-69-2] is converted thermally to formic acid and ammonia. The latter is trapped by formaldehyde, which makes it possible to titrate the residual acid by conventional methods. The water content can be determined by standard Kad Eischer titration. In order to determine iron, it has to be reduced to the iron(II) form and converted to its bipyridyl complex. This compound is red and can be determined photometrically. Contamination with iron and impurities with polymeric hydrocyanic acid are mainly responsible for the color number of the merchandized formamide (<20 APHA). Hydrocyanic acid is detected by converting it to a blue dye that is analyzed and deterruined photometrically. 

Ball color Number of holes Identity of element... 

Examination of product. Examine the propellant contained in the sampler for clarity and suspended matrer. The test method described in ASTM D1209-62 shall be used for the color measurement. The color shall not exceed the American Public Health Association color number 10... 

During the appropriate tests phthalic anhydride was smoothly esterified with 2-ethylhexanol in the mole ratio 1 4. The reaction temperature rose to 200°C. after about 15 minutes, then rose slowly up to 210°C. till the end of the esterification. Table I shows the esterification time in hours after 99.9% conversion, while continuously removing the reaction water, according to the acid number relative to monooctyl phthalic acid. Furthermore, it indicates the ester colors according to the iodine scale in milligrams iodine/100 ml., whereby 1 mg. iodine/100 ml. can be more or less compared with a dye number of 120 APHA. Since, the values are obtained with the same starting materials, it is possible to compare the color numbers. They show that with the same times, the amphoteric catalysis achieves better colors than in the reaction course containing catalytically effective acids. 

During the main manufacturing process it is possible, by using aluminum and sodium compounds, to feed the recycle alcohol more than 1000 times without risking an intolerable deterioration of the color number. 

The post color number is then calculated as follows ... 

Initial levels of brightness, post color numbers, activation energy levels, estimated rates of change at room temperature, ranking orders, and coefficients of correlation by rank are listed in Table XI. Arrhenius graphs for reflective brightness data are shown in Figure 5. 

Initial brightness values for the papers in Study No. Ill are listed in Table XV also listed are the post color numbers, activation energy values, and estimated rates of change at room temperature. In this instance, loss of reflective brightness for the two single-withdrawal pro-... 

For every colorfastness test conducted, the color change of tested specimen was evaluated by comparing it with the remnant fabric color using the Gray Scale for Color Change. In addition, the color of the resulting specimen for each test was analyzed and assigned a Munsell color number. Results are in Table III. 

The plastic color standard is the reference color control to which all color match trials are visually compared. In some cases, the standard must be returned with the match or after the match is approved. The ideal situation is to keep the color standard, labeled with the customer identification number, the in-house color number, date, and polymer type, if known. Handling, storage, age, texture, gloss, shape, size, and physical form all determine the condition of the color standard both as received and for future reference purposes. 

Terminal number at source and source location Terminal number at destination and destination location Core outer sheath color/number Core size... 

The Merck Company of Darmstadt, Germany developed the OXIFRIT FRIT-EST to measure oil quality in frying operations, especially in restaurants. The Fritest measures the alkali color number to indicate oxidized fatty acid (OFA) and the Oxifrit Test measures oxidation products in the fryer oil. Both tests are colorimetric and use a solvent-based reagent system. The test methodology is too comphcated for the restaurant personnel. 

If you changed colors in the multicolor mode, some of the colors in the normal mode may have been changed. You can alter these colors as in multicolor mode. Press SHIFT-1 to change the color of the empty pixels, and SHIFT-2 to change the color of the on pixels. (You ll be prompted to press a color number key after each SHIFT-1 or SHIFT-2 combination. Remember to press either CONTROL or the Commodore key simultaneously with the color key.)... 

In one test (ASTM D-156) for the determination of color the height of a column of the oil is decreased by levels corresponding to color numbers until the color of the sample is lighter than that of the standard. The color number immediately above this level is recorded as the Saybolt color of the oil, and a color number of +25 corresponds to water mineral, whereas the minimum color intensity reading on this scale is expressed by +30, a value normally attained by mineral oils. In another test (IP 17), in which the measurements are performed with an 18-in. cell against color slides on a scale, a color of 1.0 or under is considered water-mineral and medicinal oils will normally be 0.5 or less. Conversion scales for different color tests are available (ASTM D-1500). 

The Saybolt color test method (ASTM D-156) is used for nearly colorless waxes, and in this method a melted sample is placed in a heated vertical tube mounted alongside a second tube containing standard color disks. An optical viewer allows simultaneous viewing of both tubes. The level of the sample is decreased until its color is lighter than that of the standard and the color number above this level is the Saybolt color. 

Work on as many of the problems at the end of the chapter as you can. They review and extend the concepts and skills in the text. Answers are given in the back of the book for problems with a colored number, but try to solve them yourself first. Let s apply this approach in a unit-conversion problem. 

Problems with colored numbers are answered in Appendix E. Sections match the text and provide the numbers of relevant sample problems. Bracketed problems are grouped in pairs (indicated by a short rule) that cover the same concept. Comprehensive Problems are based on material from any section. 

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