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°).
As ultrasound is transmitted, there are parts of the wave that are compressed (increase in pressure or density) and parts that are rarefied (decrease in pressure or density). When used in diagnostic echocardiography, the frequency is usually above 20,000 Hz (20 kHz), and it is not audible to a human ear. Fig. 1.