Model 18
A/
resistor across thetransducer and peaks at the anti-resonant frequency. The Model 18A/40 is a small, very inexpensive
ultrasonic transducer that operates in the40 kHz frequency region, and can be used in applications where larger variations in
electroacoustic performance from unit to unit are acceptable. The transducer is capable
of operating as both a transmitter and a receiver. The transmitting response peaks at the
resonant frequency. The receiving response is specified with a 3.9 k
(Photograph not to scale.) SPECIFICATIONS
Housing: 18 mm diameter aluminum Total Beam Angle at -6 dB: 85° (nominal) Resonant Frequency: 40 kHz +/- 1 kHz Transmit Sound Pressure Level (SPL)at Resonant Frequency:130 dB // 1µPa / 10 Vrms at 30 cm (nominal) Transmit Bandwidth at -6 dB:1 kHz (nominal) Maximum Drive Voltage: 20 Vrms Anti-resonant Frequency:1 kHz higher than resonant frequency (nominal) Receive Sensitivity at Anti-resonancewith parallel 3.9 k resistor:-170 dBV / µPa (nominal) Receive Bandwidth at -6 dB: 2 kHz (nominal) Impedance Magnitude at Resonance: 500 (nominal) Capacitance at 1 kHz: 1900 pF +/- 25% Operating Temperature: 0°C to 70°C Storage Temperature:-40°C to 80°C All specifications are typical at 20°C andare subject to change without notice.
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ASSA P
RODUCTS C
ORPORATION 280 Lincoln St., Hingham, MA 02043 USA Tel: 781-749-4800 Fax: 781-740-2045Toll Free in USA: 800-962-7543E-mail: sales@massa.com Web Site: www.massa.com Rev. 021022