Apparatus and methods for testing acoustic probes and systems
View Patent ↗Methods and apparatus are provided for testing an acoustic device that has multiple transducing elements adapted for conversion between acoustic and electrical signals. An electrical transmission signal is generated. The electrical transmission signal is transmitted to a selected transducing element. An electrical received signal is received from the acoustic device. A reference signal is generated. A capacitance associated with the selected transducing element is determined from the reference signal. Operational characteristics of the selected transducing element are diagnosed from the determined capacitance and the electrical received signal.
1. A method for testing an acoustic device having a plurality of transducing elements adapted for conversion between acoustic and electrical signals, the method comprising:
generating an electrical transmission signal;
transmitting the electrical transmission signal to a selected transducing element;
receiving an electrical received signal from the acoustic device;
generating a reference signal with a frequency less than 100 kHz;
determining a capacitance associated with the selected transducing element from the reference signal; and
diagnosing operational characteristics of the selected transducing element from the determined capacitance and the electrical received signal.
2. The method recited in claim 1 wherein the electrical received signal corresponds to an acoustic signal converted from the electrical transmission signal and reflected from a target.
3. The method recited in claim 1 wherein the electrical transmission signal comprises a voltage pulse.
4. The method recited in claim 1 wherein transmitting the electrical transmission signal comprises routing the electrical transmission signal through a relay element configured for selective routing from a channel to a plurality of channels.
5. The method recited in claim 4 wherein transmitting the electrical transmission signal further comprises routing the electrical transmission signal through an adapter having a multichannel switch.
6. The method recited in claim 1 wherein the reference signal comprises a linear voltage ramp signal.
7. The method recited in claim 1 wherein generating the reference signal comprises generating the reference signal with a frequency less than 10 kHz.
8. The method recited in claim 1 wherein the selected transducing element comprises a plurality of selected transducing elements.
9. A method for testing an acoustic device having a plurality of transducing elements adapted for conversion between acoustic and electrical signals, the method comprising:
generating an electrical transmission signal;
transmitting the electrical transmission signal to a selected transducing element;
receiving an electrical received signal from the acoustic device;
generating a reference signal;
determining a capacitance associated with the selected transducing element from the reference signal; and
diagnosing operational characteristics of the selected transducing element from the determined capacitance and the electrical received signal, wherein:
the selected transducing element comprises a piezoelectric crystal;
the resonant frequency of the piezoelectric crystal is between 2 and 10 MHz; and
generating the reference signal comprises generating the reference signal with a frequency between 0.5 and 1.5 MHz.
10. The method recited in claim 9 wherein the electrical received signal corresponds to an acoustic signal converted from the electrical transmission signal and reflected from a target.
11. The method recited in claim 9 wherein the electrical transmission signal comprises a voltage pulse.
12. The method recited in claim 9 wherein the reference signal comprises a linear voltage ramp signal.
13. The method recited in claim 9 wherein the selected transducing element comprises a plurality of selected transducing elements.
14. A method for testing an acoustic device having a plurality of transducing elements adapted for conversion between acoustic and electrical signals, the method comprising:
generating an electrical transmission signal;
transmitting the electrical transmission signal to a selected transducing element;
receiving an electrical received signal from the acoustic device;
generating a reference signal;
determining a capacitance associated with the selected transducing element from the reference signal; and
diagnosing operational characteristics of the selected transducing element from the determined capacitance and the electrical received signal, wherein:
the selected transducing element comprises a cable connection, the capacitance deriving at least in part from a cable capacitance of the cable connection; and
diagnosing operational characteristics comprises determining that the capacitance arising from the cable capacitance is a fraction of an expected value.
15. The method recited in claim 14 wherein the electrical received signal corresponds to an acoustic signal converted from the electrical transmission signal and reflected from a target.
16. The method recited in claim 14 wherein the electrical transmission signal comprises a voltage pulse.
17. The method recited in claim 14 wherein the reference signal comprises a linear voltage ramp signal.
18. The method recited in claim 14 wherein the selected transducing element comprises a plurality of selected transducing elements.
19. A method for testing an acoustic device having a plurality of transducing elements adapted for conversion between acoustic and electrical signals, the method comprising:
generating an electrical transmission signal;
transmitting the electrical transmission signal to a selected transducing element;
receiving an electrical received signal from the acoustic device;
generating a reference signal;
determining a capacitance associated with the selected transducing element from the reference signal; and
diagnosing operational characteristics of the selected transducing element from the determined capacitance and the electrical received signal, wherein diagnosing the operational characteristics comprises:
determining that an amplitude of the electrical received signal is substantially zero; and
determining whether the capacitance is consistent with an expected value.
20. The method recited in claim 19 wherein the electrical received signal corresponds to an acoustic signal converted from the electrical transmission signal and reflected from a target.
21. The method recited in claim 19 wherein the electrical transmission signal comprises a voltage pulse.
22. The method recited in claim 19 wherein the reference signal comprises a linear voltage ramp signal.
23. The method recited in claim 19 wherein the selected transducing element comprises a plurality of selected transducing elements.