UCT12db standard : up to 3m of concrete by thrugh-transmittion method
or 1.5m of concrete by pulse-echo method
Frequency range is 10kHz..2.5MHz
UCT12db(f) standard : up to 12m of concrete by thrugh-transmittion method
or 6m of concrete by pulse-echo method
Lower cutt off frequency is about only 5kHz