Narrow-beam level detection through a tank wall
The BBDM-2MR2M is an externally mounted ultrasonic transducer for detecting liquid level without direct contact between the sensing element and the stored liquid. Its 2 MHz center frequency and 0.03-2 m reference range support evaluation for fuel and oil tanks, sealed vessels, vehicle and machinery tanks, and through-wall detection of corrosive liquids.
The specified -3 dB half-power angle is 2.4 degrees +/-10%. The narrow field makes alignment and acoustic coupling especially important because a small angular or contact error can move the sound path away from the intended liquid interface.
Main technical specifications
| Parameter | Specification |
|---|---|
| Model | BBDM-2MR2M |
| Center frequency | 2 MHz +/-5% |
| Recommended range | 0.03-2 m |
| Minimum impedance | 10 ohm +/-20% |
| Capacitance | 2,300 pF +/-20% at 1 kHz |
| Operating voltage | Peak voltage below 150 Vpp |
| Operating temperature | -40 to +80 degrees C |
| Pressure rating | Up to 10 kgf or 1 MPa |
| Beam characteristic | -3 dB half-power angle: 2.4 degrees +/-10% |
| Housing material | 2A12 aluminum alloy and PI |
| Mounting | Refer to the product dimensional drawing |
| Protection rating | IP68 |
| Weight | 240 g +/-5% |
| Cable configuration | 5 m + 1 m |
Available material and temperature configurations
| Frequency | Housing material | Operating temperature |
|---|---|---|
| 2 MHz +/-5% | 2A12 aluminum alloy and PI | -40 to +80 degrees C |
| 2,000 kHz +/-5% | Nylon | -20 to +80 degrees C |
These configurations should be treated as separate ordering options. The housing choice and its temperature range must be confirmed together rather than combining the wider temperature range with the nylon option.
Coupling and electronics
Confirm tank-wall material, thickness, curvature, coatings and the coupling method with the actual liquid and level path. The 10-ohm minimum impedance represents a substantially different electrical load from higher-impedance tank transducers, and the drive circuit must also remain below 150 Vpp. The definition and termination of the 5 m + 1 m cable arrangement require project confirmation.