Automatic control units, namely control units in the nature of vacuum manometers and vacuum gauges with automatic vacuum pump controls and timers, for test apparatus used in performing the Maximum Specific Gravity test in accordance with one or more of AASHTO T209 or ASTM D2041 for evaluating uncompacted asphalt samples or mixtures, or AASHTO T283 or ASTM D4867 for saturation of compacted asphalt samples or mixtures, or construction materials; automatic electrical control units for use with v...