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-420 Ultrasonic Leak Detector converts this ultrasonic sound into a signal that can be used to pinpoint the exact location of the equipment failure. When working in unpressurized systems or the pressure is not sufficient enough to detect or verify a leak with the Receiver alone use the Transmitter.
Signal Level Adjustment
Earphone Jack (3.5 mm)
LCD 2.5 in (6.35 cm)
1.45 x 1.93 in (36.72 x 48.96 mm)
240(RGB) x 320 pixels
TFT-LCD (262 K)
20 kHz to 90 kHz
Typical 40 kHz squarewave
±5 KHz of main noise frequency, up to three filters
4 x 1.5 V AA (LR6) alkaline batteries
2 x 1.5 V AAA (LR03) alkaline batteries
Power Consumption (typical)
Battery Life (typical)
105 hours (Alkaline)
60 hours (Alkaline)
Low battery indication
Yes (Red LED)
Approx. 0.518 lb (0.235 kg)
Approx. 0.335 lb (0.152 kg)
7.547 x 2.984 x 1.791 in (183 x 75 x 43 mm)
5.295 x 2.559 x 1.326 in (137 x 65 x 33 mm)
60 minutes when in idle
-4 °F to 122 °F (-20 °C to 50 °C)
-4 °F to 158 °F (-20 °C to 70 °C)
Electromagnetic Compatibility (EMC)
EN 61326-1 Korea (KCC): Class A Equipment (Industrial Broadcasting & Communication Equipment)   This product meets requirements for industrial (Class A) electromagnetic wave equipment and the seller or user should take notice of it. This equipment is intended for use in business environments and is not to be used in homes.
ULD-400 Series Overview
Find ultrasonic leaks easily with the ULD-400 Series Ultrasonic Leak Detectors.
ULD-400 Series Adjusting Signal Strength
Learn how to pinpoint leaks by adjusting Receiver sensitivity.
ULD-400 Series Noise Filter
The Receiver will automatically detect and and filter out up to three main noise frequencies.
ULD-400 Series De-pressurized Systems
Use the Transmitter to emit an ultrasonic sound readable by the Receiver in systems without significant pressure.