Metal trace detection lab: MS of test equipment with brilliant light on and off, same equipment with mechanical arm in and out. CS of computer consol, print of numbers. CU of arm, of computer with numbers on. MS of technician removing water sample from plastic container. MCSs of technician setting vial of water for ph test. CS of ph monitor, of technician pushing "on" button. ECU of monitor dial needle moving from 9 to 4 and vice versa. MCS of "blue" test machine light on, with flashing green and red smaller lights, of arm of same machine moving up and down. MCU of red computer numbers flashing on and off. MCU of circular disc with containers of water being set on "spinner". MCUs of computer typewriter sheet with word "aluminum" printed on.