If you are tired of carrying around preamplifiers, tying plastic bags around them when it rains, trying to attach them to the structure so they won't fall off, and worried about damage that occurs if you happen to drop one from several feet to a concrete deck, --then read on. You say; "Well, one way around this problem is to use an integral preamplifier transducer, but they aren't very reliable, not very shock resistant, they do not come in the different frequency ranges I wish to work in and I have to build a special magnetic hold-down because they are bigger than the standard transducer." We have good news for you! All of the DECI transducers that are supplied in the standard M, Q, and H cases can now be purchased with integral electronics. So if you are accustomed to using a SE150-M, an SE900-MWB, or SE375-M you can now purchase this same size transducer with 10dB of gain and capable of driving very long cables without signal loss. These transducers are supplied with the same high reliability as the standard version. This is due to the special backing material used inside each transducer to protect it from shock, vibration, and water intrusion.
Figure 1 shows ultrasonic calibration curves for a standard SE150-M, and the SE150-MI (internal electronics). Both transducers are identical in size, therefore the standard magnetic hold-down (MAG80) will work equally well with both transducers. The 1000J power adapter is required to supply +15 volts DC to the transducer and condition the signal. The 1000J is powered with a standard laboratory power supply that will output +15 VDC and 10 milliamps of current. For multiple channel operations we will be happy to quote an instrument that will power and condition all channels. We can also supply the transducers with an integral waveguide if needed for high temperature operation.
Note from Figure 1 that the transducer containing the electronics shows to be approximately 16 dB more sensitive than the standard SE150-M driving 4 foot of cable. The electronics in the transducer have a gain of only 10dB, the additional signal gain is derived from the elimination of losses due to cable capacitance when using a standard transducer and preamplifier.
If you are tired of lugging around preamplifiers, give us a call and we will offer you an economical solution to this problem.