Top radiator hose-sensor

My '75 1500 Midget has a device tee-d midway into the top radiator hose. It
has a sensor with 4, 1/8th inch vacuum line connectors as part of the smog
system. I don't see any references in shop manuals or parts catalogs
showing this device. Anyone have a clue what this is?

Thanks.

Gerard



G G              Gerard Chateauvieux
 E A
  R R        pixelsmith@gerardsgarage.com
   A A
    R G          Pixelsmith  on  Duty
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      S      http://www.gerardsgarage.com