11.   For automatic operation, Roboguard is fitted with infrared sensors that allow it to track people as they move.

12.   He convinced them that there was a secret infrared sensor picking up their underwater routes, when all the time it was Allied code-breaking that tracked them.

13.   He moves quietly along the right-hand side of corridors and through doorways, pausing any time his infrared sensors lock on a nearby person.

14.   Heat-detecting infrared sensors have failed to spot the anti-government recluse and former airborne soldier in the thick woods and mountainous terrain.

15.   However, an Air National Guard helicopter with infrared sensors arrived on the scene and planned to continue searching in the dark.

16.   In another room, a ball rolls down a ramp and through an archway strung with fiber-optic infrared sensors.

17.   In Melilla, the local authorities have installed a barbed wire fence and infrared sensors by way of a border.

18.   Infrared sensors help the robots find things and avoid obstacles.

19.   Infrared sensors, which detect the presence of a passenger by measuring body heat, are also promising.

20.   Investigators said the problem might have been a leak in a pipe that cools infrared sensors, blinding the interceptor in the last six seconds of the flight.