Container, large enough to permit immersing the wire basket Suitable  equipment  for  suspending  the  wire basket  from  the  center  of  balance  scale  pan Thermometer,  general  laboratory PROCEDURE.—    Perform  the  test  in  the following steps. You must complete the first step as  quickly  as  possible  after  surface-drying  the sample. 1.  Determine  the  weight  of  the  saturated- surface-dry  sample  and  container.  This  weight minus  the  tare  weight  of  the  container  is  the weight of the saturated-surface-dry soil that you should  enter  in  block  7e  (fig.  15-33). 2.  Determine  the  weight  of  the  wire  basket suspended in water. Record this weight in block 7g  (fig.  15-33). 3. Place the sample in the basket and immerse the basket and sample in water. (Hang the basket from the balance and support the container so that the basket hangs freely in the water.) Read the weight and record it in block 7f (fig. 15-33). Sub- tract the weight of the empty basket suspended in water, Step 2 above, to determine the weight of the saturated soil in water. Record this weight in  block  7h  (fig.  15-33). 4. Measure and record the temperature of the water  and  soil.  Enter  this  temperature  in  block 7b  (fig.  15-33). 5.  Determine  the  ovendry  weight  of  the sample  and  enter  the  results  in  block  7k (fig.15-33). 6.  From  the  recorded  information,  you  may now calculate both the bulk specific gravity (G~) and the apparent specific gravity  (Ga) using the following   formulas: and Specific Gravity of Composite Sample After  determining  the  specific  gravity  of  solids (G.)   and  the  apparent  specific  gravity you  can  calculate  the  specific  gravity  of  an  en- tire  soil  sample  (both  larger  and  smaller  than a  No.  4  sieve).  To  do  so,  use  the  following formula: Enter  this  composite  specific  gravity  in  the remarks block of the data sheet. Note, too, that you  should  also  enter  in  the  remarks  block  the percent of materials that is retained on, or passes, the  No.  4  sieve. Comment Regarding Correction Factor (K) Refer again to figure 15-33. In this figure, you see the values of  G~, G., and G~  that  were  ob- tained using the correction factor (K). Now, if you were  to  disregard  K  and  recalculate,  you  would obtain  values  of  the  following:   G.  =  2.7939, G= = 2.6638, and  Gm = 2.4471. As you can see, these values, obtained without the correction fac- tor, are hardly different than the values obtained with  the  correction  factor.  Therefore,  unless unusually accurate precision is required, the cor- rection  factor  may  be  disregarded. ATTERBERG  LIMITS As you previously learned, fine-grained soils are  not  classified  under  the  Unified  Soils  Clas- sification  System  on  the  basis  of  grain  size distribution. They are, instead, classified on the basis  of  plasticity  and  compressibility.  The  At- terberg  limits  are  laboratory  classification  criteria used for classifying fine-grained soils. As an EA3, you will be responsible for the performance of the Atterberg limits test. A clay or related fine-grained soil, when dry or  nearly  dry,  has  a  semisolid  consistency.  As moisture  content  increases,  a  point  is  reached where the material has a plastic (putty like) con- sistency. This point is called the PLASTIC LIMIT (PL). As moisture content continues to increase, the  material  remains  plastic  over  a  certain  range. However,  at  a  point  called  the  LIQUID  LIMIT (LL),  the  consistency  of  the  material  finally changes  to  semiliquid. The upper and lower limits of the plastic range (that is, the liquid and plastic limits) are called ATTERBERG LIMITS. These limits were named after a Swedish scientist who developed the con- cept of the limits. The liquid limit (LL) is simply 15-29