TM 10-6640-215-13 2-8. OPERATING PROCEDURES -continued. (6)   Verify  operation  by  observing  vacuum  pressure  gage.    Vacuum  is  indicated  on  gage  in  inches  of  mercury (Hg).  The vacuum pump has a 58-liter per minute free air capacity with a vacuum of 0.1 micron (0.001 mm Hg). NOTE Gurgling sound occurs during operation in varying degrees under four  conditions  of  performance:  when  operating  at  high  pressure as  in  the  beginning  cycles  of  evacuation  of  a  chamber;  when  the oil  level  in  the  pump  reservoir  is  too  low:  when  a  large  leak  is present in the system; and when the vented exhaust valve is open. (7)   To shut down the vacuum pump, close the pump intake, then set the vacuum pump controller switch to the STOP position. e. Sampling and Caging Kit Operation (Refer to Figure 2-20).  This kit is completely portable and self-contained.  It consists  of  the  carrying  case,  which  is  divided  into  sections  to  hold  the  major  items  of  equipment,  an  API  gravity computer,  a  cupcase  thermometer,  a  hydrometer  cylinder,  gasoline  indicting  paste,  water  indicating  paste,  innage tape and bob, a weighted beaker sampler, and standard hydrometers. Setting the Kit Up for Operation. (1)   Clean innage tape with cheesecloth.  Ensure equipment is clean, dry, and free of dirt. (2)   Check mercury columns in hydrometer and cupcase thermometer.  If mercury column is separated or glass cracked, replace the instrument. (3)   Check thermometer readings with other thermometers in the area to ensure they read the same. (4)   Before a product is sampled or gaged, rinse the containers with the same type of product to be sampled or gaged. WARNING Never gage or sample a product in a tank if there is an electrical storm or  a  source  of  sparks  in  the  area.    Failure  to  comply  with  this  warning could result in serious injury or death. (5)   Conduct tests in accordance with pamphlets stored in packet of case which contain ASTM test methods. f. Anti-Icing Additive Test Kit Operation (Refer to Figure 2-21).  The kit is portable and self-contained.  It consists of carrying case, refractometer, a separatory funnel, support base with rod and ring, aluminum dishes, piston pipets, a graduated cylinder and a bottle with screw cap. Anti-Icing Additive test Kit Setup and Operation. (1)   Using a clean, dry container, procure a l-pint (0.473 1) sample of fuel to be tested. 2-55