Damage type to protect against:
Angel - All
Amarr Navy - EM & Thermal
Blood - EM & Thermal
Caldari navy - Kinetic & Thermal
Gallente - Kinetic & Thermal
Guristas - Kinetic & Thermal
Khanid - EM & Thermal
Mercenary - EM & Thermal & Kin
Mordus - Kinetic & Thermal
Sansha - EM & Thermal
Serpentis - Kinetic & Thermal

Main Damage type to shoot at the enemy:
Angel - Kinetic & Explosive
Guristas - Kinetic
Serpentis - Thermal
Mordus - Thermal & Kinetic
Blood - Thermal
Sansha - Thermal
Angel - Explosive
Mercenary - Thermal

Radar Sensors are primarily found on Amarr, Blood Raider and Sanshas ships.
Gravimetric Sensors are primarily found on Caldari and Guristas ships.
Ladar Sensors are primarily found on Minmatar and Angel ships.
Magnetometric Sensors are primarily found on Gallente, Serpentis and ORE ships.