Low-frequency wetted transducer for liquid flow systems
The BBFM-Q21K is a 21 kHz wetted ultrasonic flow measurement transducer designed for industrial liquid flow meters, pipe velocity measurement and water-treatment flow monitoring. It can also be considered for embedded flow measurement modules.
The half-power beam angle is 28.5° ±10% at -3 dB. The operating temperature range is -40 to +80°C, the pressure limit is 10 kgf or 1 MPa, and the protection rating is IP68.
Acoustic, electrical and mechanical specifications
| Parameter | Specification |
|---|---|
| Model | BBFM-Q21K |
| Center frequency | 21 kHz ±10% |
| Minimum impedance | 130 Ω ±20% |
| Capacitance | 68,000 pF ±20% at 1 kHz |
| Operating voltage | Peak voltage <3,000 Vpp |
| Operating temperature | -40 to +80°C |
| Pressure rating | ≤10 kgf or 1 MPa |
| Half-power beam angle | 28.5° ±10% at -3 dB |
| Housing material | 304 stainless steel + PI |
| Protection rating | IP68 |
| Weight | 12.2 kg ±5% with a 20 m ±0.3 m cable |
Electrical and cable specifications
The drive and receive circuit should be matched to the 130 Ω ±20% minimum impedance and 68,000 pF ±20% capacitance at 1 kHz. Peak voltage must remain below 3,000 Vpp.
The 12.2 kg ±5% weight applies to the version with a 20 m ±0.3 m cable.
Applications
- Industrial liquid flow meters
- Pipe velocity measurement
- Water-treatment flow monitoring
- Embedded flow measurement modules