Here are the specs:
- Resonant Frequency: 1.2 MHz
- Material: PZT-5H
- Shape: cylinder (length 0.05 inches, width 0.05 inches, wall thickness 0.01 inches)
- Capacitance: 420-550 pF
- Bandwidth: around 200KHz.
- Maximum Input Voltage: around 1kV (limiting factor is wire insulation and our sonomicrometer board circuitry)
- Power Consumption/Efficiency: we use a very small duty cycle (about 0.009%)
- Bandwidth: Our 2 mm crystals operate at about 2 mHz. Due to the nature of the crystals the bandwidth is very narrow at about 200 kHz.
- Load, Capacitive or Inductive: The crystals act as a capacitive load when out of the bandwidth of operation. Then within the bandwidth they operate as an inductive load. There different electrical models for the operation of the crystals, however the most widely accepted is the Mason, and KLM models.
- Nominal Input Voltage: We pulse the crystals with a short duration pulse with a peak to peak voltage of about 100v.
- Maximum Input Voltage: Maximum input voltage is near 1kV. The limiting factor is more likely the wire insulation and the PC board circuitry, rather than the actual crystals.
- Power Consumption and Efficiency: We use a very small duty cycle ( about 0.009%)
- Preferable Input Waveform: Due to the narrow bandwidth of the crystal they are very accepting to the type of pulse that they receive. However, for optimal performance, you want to keep the fundamental frequency of the excitation pulse near operational frequency of the crystal.
The typical use for these crystals is via a 60 volt pulse charge when we ping them. This excitation pulse is delivered as square-wave which lasts anywhere from 125 to 500 nsec (the user can select this pulse duration in the acquisition software interface of our sonomicrometer).
When the crystals are operating is resonant mode, they behave as inductors. When the crystals are operating in non-resonant mode, they behave as capacitors.
I will be using this crystal in a non-standard way to create an artifact in the ultrasound video I will be capturing (it will show up as ‘sparkle’) such that I can synchronize the video capture with a motion capture system by linking the first frame with noise/artifact with the first frame that the LED is lit in the motion capture system.