Level measurement ultrasonic transducer BBDM-21KR25M

Overview
The BBDM-21KR25M is an air-coupled ultrasonic transducer with a 21 kHz center frequency and a reference range of 1.0 to 25 m. It is designed for long-range level measurement, industrial distance sensing, collision avoidance and area/target detection in large vessels and open environments. The transducer body is PTFE with an IP68 protection rating; verify chemical compatibility of PTFE with your process fluids before deployment.

Technical specifications
Parameter — Specification
Model — BBDM-21KR25M
Center frequency — 21 kHz ±5%
Recommended range — 1.0–25 m
Minimum impedance — 1,100 Ω ±20%
Capacitance — 11,000 pF ±20% at 1 kHz
Operating voltage — Peak voltage below 1,500 Vpp
Operating temperature — -40 to +80 °C
Pressure rating — Up to 3 kgf / 0.3 MPa
Beam characteristic — -3 dB half-power angle: 13° ±10%
Housing material — PTFE
Protection rating — IP68
Weight — 1,480 g ±5% (with 10 m ±0.3 m cable)

Tank geometry and echo clearance
The 13° half-power angle defines the main acoustic field. Internal structures such as fill pipes, ladders, braces and sloped surfaces may return reflections that precede the true liquid surface echo. The lower limit of the reference range is 1 m; verify installation geometry to avoid blind zones and false echoes.

Technical characteristics

• Model: BBDM-21KR25M
• Center frequency: 21 kHz ±5%
• Recommended/reference range: 1.0–25 m
• Minimum impedance: 1,100 Ω ±20%
• Capacitance: 11,000 pF ±20% at 1 kHz
• Operating voltage: Peak voltage below 1,500 Vpp
• Operating temperature: -40 to +80 °C
• Pressure rating: Up to 3 kgf / 0.3 MPa
• Beam characteristic: -3 dB half-power angle 13° ±10%
• Housing material: PTFE
• Protection rating: IP68
• Weight: 1,480 g ±5% (with 10 m ±0.3 m cable)