YONGHWAN KIM 12 
 이인철 45 
 In order to measure steel corrosion in mortar by a transient electro - magnetic ( TEM ) Method , the development of the sensors have been studied . The sensors were made of enamelled wire with diameter of 0 . 25 mm and Acril . The sensor configuration was used as a coincident loop type . The secondary electro motive force ( EMF ) was measured with SIROTEM III . The accelerator was equipped with the SIROTEM III . The accelerator permits the transmitter to turn off approximately 10 ~ 15 times faster than normal . The high resolution time series used for very shallow or high resistivity investigation was selected . The steels were embedded in mortar which were made from sand : cement : water ratio of 2 : 1 : 0 . 5 . The mortar specimen was 50 cm long , 20 cm wide and 10 cm thick . To investigate steel corrosion in mortar , the sensors used were with 2 $\ times $ 2 $ cm ^ 2 $( 3 , 6 , 9 $\ Omega $), 3 $\ times $ 3 $ cm ^ 2 $( 3 , 6 , 9 $\ Omega $) and 6 $\ times $ 6 $ cm ^ 2 $( 3 , 6 , 9 $\ Omega $). The obtained result obtained showed that the sensor 8 ( 6 $\ times $ 6 $ cm ^ 2 $, 6 $\ Omega $) was the proper sensor for the measurement of steel corrosion in mortar . 
 함주혁 85