FALSE AND NUISANCE ALARM PERFORMANCE OF THE SENSORS WAS ALSO MONITORED. NO SINGLE SYSTEM WAS SHOWN TO BE SUPERIOR IN ALL ASPECTS OF PERFORMANCE. OBTAINING A GOOD BALANCE BETWEEN SENSITIVITY AND THE RATE OF WIND-INDUCED NUISANCE ALARMS WAS NOTED AS THE PRINCIPAL PROBLEM IN THE CONTINUING DEVELOPMENT OF FENCE SENSOR SYSTEMS. THE TESTS PERFORMED INDICATED THE ADVANTAGE OF USING PROCESSING LOGIC FOR BOTH CABLE-TYPE AND SWITCH-TYPE SENSORS. THIS LOGIC HAD THE EFFECT OF INCREASING THE WIND SPEED THAT COULD BE TOLERATED WITHOUT EXCESSIVE NUISANCE ALARMS.