Cold differential test

Cold Differential Test Pressure - The cold differential test pressure (in kPa gage) is the pressure at which the valve is adjusted to open on the test stand. This cold differential test pressure includes the corrections for service conditions of back pressure and/or temperature. 

Then the Cold Differential Test Pressure (set pressure on the test bench) will have to be reduced by the amount of the backpressure to obtain the correct set pressure on the installation CDTP = Set - BP. 

Cold Differential Test Pressure Units 52. Manufacturer... 

Cold Differential Test Pressure Units 60. Selected Orifice Area (in square in.) ... 

Society s Cold Test is used for salad oils. Palm olein is assessed by its cloud point and sometimes by a cold stability test in which the length of time for which the oil remains clear at 18-20 °C is measured. Other tests of importance are the solid fat content by NMR or dilatometry and differential scanning calorimetry. Deffense and Tirtiaux (1982) published HPLC chromatograms for the raw materials and products of the fractionation of palm oil and beef tallow. 

The following analytical techniques seem to be adequate for the concentrations under consideration copper and nickel by Freon extraction and FAA cold vapour atomic absorption spectrometry, cobalt by Chelex extraction and differential pulse polarography, mercury by cold vapour atomic absorption absorptiometry, lead by isotope dilution plus clean room manipulation and mass spectrometry. These techniques may be used to detect changes in the above elements for storage tests Cu at 8 nmol/kg, Ni at 5 nmol/kg, Co at 0.5 nmol/kg, Hg at 0.1 nmol/kg, and Pb at 0.7 nmol/kg. 

The different chemical compounds used as wax crystal modifiers do not all provide ideal performance under every circumstance. Various tests have been designed to help differentiate the performance of one wax crystal modifier over another. For example, a modifier may be quite effective at controlling wax crystal formation to enable a fuel to flow by gravity from a storage tank to a pump. However, once past the pump, the modifier may not effectively reduce the wax crystal size and shape to allow cold fuel to flow effectively through a line filter. The result is wax accumulation on the filter media, plugging of the fuel filter, and halting of fuel flow. A different wax crystal modifier or a product with wax dispersant properties may be required to permit effective fuel filtration. 

Assessing the results of such tests requires considerable experience. It is important, for example, to differentiate between the stability of a product and its performance. A material smelled in a sample of dry detergent powder may show poor performance and yet be stable, making a valuable contribution to the performance of a perfume on washed fabric. Its failure to perform in the base, even on cold storage, should not necessarily be attributed to instability. 

Cellulose di- and triacetate fibres (CA, CT) as well as acrylic fibres (polyacrylonitrile, PAN) are all soluble in the zinc chloride-iodine reagent. An initial differentiation is made using the acetone test on a watchglass only CA and CT fibres dissolve (evidenced by a cloudy evaporation residue). Differentiation between CA and CT fibres CA dissolves in Frott6 II reagent (see Table 8.1), CT only swells. Results are similar in zinc chloride/formic acid, but with a less distinct difference (CT swells more markedly). PAN fibres dissolve in cold concentrated nitric acid and in dimethylformamide at 100 °C. They swell in boiling 85 % formic acid and decompose at about 280 °C without melting. 

The samples are placed in an upright position in a tray which is immersed into hot water for a given time, then transferred to a cold water bath. Temperatures of both baths are closely controlled. Samples are examined before and after the tests for outside surface cracks or breakage. The amount of thermal shock a bottle will withstand depends on its size, design and glass distribution. Small bottles will probably withstand a temperature differential of 60-80°C, and 1 pint bottles 30-40°C. A typical test uses a 45°C temperature difference, hot to cold. 

Solubility Tests Fibers of cellulose esters (e.g., cellulose acetate, cellulose nitrate) dissolve in acetone or chloroform, polyamide fibers dissolve in cone, formic acid, and polyacrylonitrile fibers dissolve in cold, cone, nitric acid and in boiling dimethylformamide. Polyester fibers are soluble in 1,2-dichlorobenzene or nitrobenzene, while wool dissolves in potassium hydroxide. Polyamide fibers can be differentiated by their different solubilities in 4.2 N hydrochloric acid polyamide 66 (nylon 66) is soluble upon heating, and polyamide 6 (nylon 6) dissolves at room temperature (4.2 N HCl is prepared as follows one carefully pours 35 ml of fuming (12.5 N) HCl into 65 ml of water). 

Principal component analysis is another statistical technique that has been applied to the results of profile analysis [55]. Ales and lagers were examined and two-dimensional plots of the results using the first two principal components as axes showed resolution of the ales from the lagers and the close proximity of the majority of duplicate samples. Profile analysis has also been used to differentiate various brands of whisky [56]. Throughout the work on profile analysis hedonic expressions have been strictly excluded but other workers [57] have used principal component analysis to classify Continental European beers correctly as good, average or poor on the basis of nine physicochemical parameters colloidal stability (7 days at 40°C/1 day at 0°C), cold sensitivity (24 hours at 0°C), brightness at 12°C, six months test, the content of p-phenylethanol, ethyl caprylate, isoamyl acetate, and isobutanol and foam stability. 

If witherite and strontianite are to be differentiated, milligram quantities of the powdered carbonates are mixed in micro crucibles with about 0.5 g of ammonium sulfate and carefully heated until no more fumes of sulfur trioxide appear. The carbonates are transformed to sulfates by this treatment. The cold residues are spotted with a 0.2 % solution of sodium rhodizonate. A red color is formed with the portion originally containing strontianite. This test succeeds in the presence of calcite also, because, like barium sulfate, the calcium sulfate remaining after the fuming with ammonium sulfate does not show any reaction with sodium rhodizonate. 

Solubility in Cold Concentrated H2SO4.—The sulfuric acid test is of value in differentiating between Groups V and VI. Compounds falling in Groups I, II, III, and IV, as well as indif-... 

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