The SDT340 TankTest is an ultrasonic acoustic-vacuum leak detection system designed for integrity testing of underground storage tanks (USTs) containing fuel, oil, or chemicals. It uses a non-invasive method: two 32 mm acoustic sensors—one red, submerged in the liquid; one black, positioned above the liquid surface—measure background ultrasonic noise in dBµV, after which an integrated vacuum pump applies a calibrated underpressure of ±250 mbar to the tank. Any perforation or crack in the tank shell draws air inward, generating an ultrasonic signal that the sensors detect and the operator can listen to in real time through noise-cancelling headphones. The method requires no tank emptying, no cleaning, and zero liquid stabilization time—tests can be performed on tanks up to 80 m³ in any fill state.

How does the acoustic vacuum method compare to hydrostatic testing?

Traditional hydrostatic tank testing requires the tank to be emptied, cleaned, filled with water, pressurized, and monitored for pressure decay—a process that can take an entire day and generates contaminated water requiring disposal. The SDT340's acoustic vacuum method achieves the same integrity verification in a fraction of the time: the operator installs the sensors through the manhole, seals the openings with the supplied conical rubber plugs and gauges, applies the vacuum, and reads the result within minutes. Because it tests the tank in its normal operating state—with the stored product still inside—it eliminates the cost and environmental burden of product transfer and wastewater disposal. The method has been approved by licensing bodies in Belgium, France, and the USA since 1995 and complies with VLAREM II underpressure limits of ≤30 kPa (300 mbar) for recognized oil tank technicians.

How does the Leak Simulator validate the test?

The SDT340 TankTest kit includes a Leak Simulator—a calibrated device with six known leak orifices and a connecting tube—that serves as a built-in validation tool. After completing a tank test, the operator connects the simulator and runs the test sequence again: if the system correctly identifies and measures the simulated leaks, it confirms the test was executed properly and the equipment is functioning within specification. This protects the technician against claims of faulty testing and provides auditable proof that the instrument detected a known leak at the time of the test. The SDT TankTest Reporter software (included on USB, free license) generates automatically numbered, tamper-proof reports combining measurement data, audio recordings, and Leak Simulator verification into a single compliance document.