Ultrasonic transit-time ultrasonic transducer BBFM-Q135K

immersiblehigh-frequencymeasurement

Overview
The BBFM-Q135K is a 135 kHz ultrasonic transducer designed for industrial gas flow metering and transit-time measurement modules. It supports acoustic path lengths from 0.10 to 1.5 m and delivers a narrow beam (half-power beam angle 7° ±10% at -3 dB). The device is housed in stainless steel and rated IP68 for use in harsh environments.

Technical data for system design

• Model — BBFM-Q135K
• Center frequency — 135 kHz ±5%
• Recommended range — 0.10 to 1.5 m
• Minimum impedance — 500 Ω ±20%
• Capacitance — 1,900 pF ±20% at 1 kHz
• Operating voltage — Peak voltage < 300 Vpp
• Operating temperature — -40 to +80 °C
• Pressure rating — ≤3 kgf (0.3 MPa)
• Half-power beam angle — 7° ±10% at -3 dB
• Housing material — Stainless steel
• Protection rating — IP68
• Weight — 330 g ±5% with 1 m cable

Gas metering applications

• Industrial gas flow meters
• Gas meters for custody or process monitoring
• Gas velocity measurement
• Transit-time gas measurement modules

Excitation and receive-side requirements
Drive and receiving electronics must be matched to the specified minimum impedance (500 Ω ±20%) and capacitance (1,900 pF ±20% at 1 kHz). Peak drive voltage must remain below 300 Vpp. Ensure operating conditions remain within -40 to +80 °C and below the stated pressure limit. The IP68-rated stainless steel housing enables immersion and washdown where required.

Features / Technical specifications

• Model: BBFM-Q135K
• Center frequency: 135 kHz ±5%
• Range: 0.10–1.5 m (recommended)
• Impedance: ≥500 Ω ±20%
• Capacitance: 1,900 pF ±20% @1 kHz
• Peak drive: < 300 Vpp
• Temperature: -40 to +80 °C
• Pressure: ≤3 kgf / 0.3 MPa
• Beam angle: 7° ±10% (-3 dB)
• Housing: Stainless steel
• Ingress protection: IP68
• Weight: 330 g ±5% (with 1 m cable)