1 M or m â prefix designating a number in thousands (not to be confused with SI prefix M for mega-or m for milli).
There are two types commonly referred to as: 'Shallow' and 'Deep' water. The differences are not only in the Frequency but also in the Beam Width and they are as follows: 'Shallow' water HST-WSBL 106-72 Transducer will operate on 2 frequencies on the HDS models: 200 (20Â°) & 83KHz (60Â°). 'Deep' water HST-DFSBL 106-77 Transducer will operate on 2 frequencies on the HDS models: 200KHz (12Â°) & 50KHz (35Â°).
For the finai frequency, 75 Hz, an Instron Model 1603 electromagnetic resonancemachine capable of 50 to 400 Hz was used.We auemnpted to achieve 150 Hz with this specimen configuration, but the Instron Model 1603 machineonly allowed a peak of 75 Hz for this size speciren.