Document 0JkoO8EyLXdbK4y37vbJJnJVV

DIRECTIONS FOR TEST NO. Id-10-^2 SUBJECT: Speolflo Gravity of Liquid Aroolors METHOD: Westphal Balance ; . __ ____ iI ' General .- ; V Speolflo gravity; Is determined by means of the . . Westphal balanoe. The temperatures at which the specific r gravities of liquid Aroolors are taken vary with the vis cosity Of the liquid. The specifications for eaoh Aroolor should State the temperature for both the Aroolor and the f- Water to which comparison of gravity is made. In plant practice, specific gravities of Aroolors containing up to 54$ ohlorine are made at 65/65C while speolflo gravities of Aroolors containing 60-52$ chlorine are made at 9Q/90C. > Specific gravities of any of the Aroolors may be made at 25/25 by use of the A.S.T.M. method for road tars, asphalt cements, soft tars pitches, serial designatlon D70-27, 1927 (described in Bureau of Standards Misoellaneous Publication No. 110, Standards and Speoiflcatlons fbr Nonmetallio Minerals and their products, page 125.) . .--v Apparatus............: . Westpbal Balance; Similar to Elmer and Amend Catalogue No. 16930. Plummet need not have theimometer soale to 90C but should not be subjeot to Injury by use at this temperature. ;^ Cylinder: Fyrex glass hydrometer jar 1.5" x 6*. Thexmometer; Use thexmometer which has been checked for accuracy of scale in the range used. Procedure . Place the westphal in such position that the plummet is 7 - 9 inches above the work bench. By means of the leveling screw, adjust the Westphal balance to show zero reading with a clean dry plummet In air. Suspend the plummet during adjustment in a empty cylinder to pro tect the apparatus from air currents. Heat the Aroolor to be tested to a temperature about 15 higher than the temperature at which determin ation is to be made. For example, if specific gravity Is wanted at 65C, the Aroolor should be heated to about 8dC. Then pour the heated Aroolor into a clean Pyrex cylinder whloh has been warmed by setting at edge of hot plate. . - . . .. 'Ww?*;"'7 * . .. DSW 330747 v STLCOPCB4077391 Page 2 DIRECTIONS FOR TEST NO. H-10-^2 SUBJECT; Speolflo Gravity of liquid Aroclors METHOD: Westphal Balance The cylinder should be filled with the Aroolor to within about 1 inch of the top. , \ v>s-V` ' v. . . ` ' /I* ' v v-'y : >av.`,.'A>ihwv^` . . . - :-.-',;.C;.-. Hr .. ^'H^rjoiow 'tke' Aroolor n the cylinder to air cool until the temperature is about 7 degrees above that de~ sired, then piaoe the cylinder in a hot water bath which is at a temperature about 5 degrees above the desired tem perature. A liter beaker containing sufficient water to be equal to or above the level of the Aroolor in the cy linder is a satisfactory water bath. In case the Specific Gravity is to be taken at 90/90, a glycerin bath should be substituted for the water bath to avoid the water vapor with its condensation on the Westphal balance which is present if water Is used at high temperatures such as 95C Without disturbing the adjustment of the Westphql whloh is set to read zero with plummet in air, place the cylinder containing the Aroolor in such position that the plummet is immersed in Aroolor end add weights to the beam of the Westphal until the beam is again level. The plummet should now be completely immersed as well as about 1/2" of the suspension wire and the plummet should not touch the cylinder at any poiht. Stir the Aroolor with a thermometer at frequent intervals until the desired temperature just is reached. At this point the weights are quickly adjusted un til equilibrium is obtained and the reading noted. Saving obtained the reading for Aroolor at the desired temperature, the specific gravity is obtained by dividing this figure by the reading when the plummet is immersed in pure water at the same temperature. The read ing fbr water is obtained In the same manner as for Arocloi Sinoe the reading for water is constant, provided there are no errors in weights or Westphal, this figure need not - be determined with each Aroolor test. The figure for watei which Is used as a oonstant should, however, be checked once amopth or whenever greatest accuracy is needed. The readings fbr water at 65C and $Q9G are respectively 9o2o and *972. ' .- Calculation of Result Example 1. Assume readings as follows: Westphal reading with plummet in air Westphal reading with plummet in Aroolor at 65C Westphal reading with plummet in water at 5*0 Then sp.gr. at 65/65C l.|02^ 1*5283 Zero 1*5025 *9o2o '' ^^ DSW330748 STLCOPCB4077392 .* I /= / *. r... - '. zz.&.-, . . - 3Pag . DIRECTIONS FOR TEST NO, 14-10-52 SUBJECT; Specific Gravity of Liquid Aroolors METHOD: ffeatphal Balance , Example 2* Assume readings as follows: . /' v> t> - -. 4 - tfestphal reading with plismaet In air S*-,"-iWestphal reading with plummet in Aroolor at gOC Westphal reading with plummet In water at 900 Then sp. gr. at 9O/9O0C 1.5435 * 1*5958 Zero 1*5435 *9of2 v.., . , : Notes - / .. .- - . , ' 1. The weights used with the Westphal halanoe should be checked periodically by weighing each on an analytical balanoe. . . ^ 2. The adjustment of the liquid to the exact temperature desired is most important. Do not allow to cool rapidly and stir frequently enough to maintain a uniform temperature from top to bottom in the cylinder. 4BG-hp Copied 6/12/35 'V " oSNM 330749 STLCOPCB4077393