• ULD-420
  • Usually ships in 1-2 weeks



  • ULD-400-R receiver
    • Sensitivity adjustment
    • 20 to 90 kHz frequency range
    • 75 mA typical power consumption
    • 2.5in LCD display with bargraph
  • ULD-400-T transmitter
    • Three signal strengths
    • 40 kHz typical squarewave frequency
    • 33 mA typical power consumption
  • -4 to 122°F (-20 to 50°C) operating temperature
  • <80% RH operating humidity
  • Detachable tubular extension for hard-to-reach areas
  • IP40

What's in the Box

  • ULD-400-R receiver
  • ULD-400-T transmitter
  • Headphones
  • Earbuds (for use with hard hat)
  • PB-1 power parabola
  • TEA-1 flexible tubing adapter
  • TE-1 tubular extension
  • Hard carrying case
  • 4 x AA batteries
  • 2 x AAA batteries


The Amprobe ULD-420 ultrasonic leak detector kit is designed for easy inspection and troubleshooting. When equipment begins to fail due to an air or gas leak or vibration, or electrical discharge, the leakage point emits an ultrasonic sound wave that is above the natural range of human hearing. The ULD-400 series leak detector converts this ultrasonic sound into a signal that can be used to pinpoint the exact location of the equipment failure. The large LCD bargraph clearly shows the strength of the leak, allowing the user to easily identify its source and to use the headphones to hear the converted audible sound.

When working in unpressurized systems, or the pressure is not sufficient enough to detect or verify a leak with the receiver alone, the transmitter can be used to generate the ultrasonic signal. In extremely noisy environments with strong ultrasonic noise generated by running machinery or equipment, the receiver's filter function can filter out up to three main noise frequencies that would otherwise hide the noise of the fail.

Amprobe ULD-420 Ultrasonic Leak Detector Kit Applications

  • Compressed air or other gases (except combustible gases)
  • Plumbing
  • Electrical and mechanical systems
  • Valves, tanks and pipes
  • Heat exchangers, boilers and condensers
  • Air conditioning and refrigeration systems
  • Motors and machinery