Leaks in compressed air and gases pipe networks can cause thousands of losses. Nowadays the saving of energy is an important topic in all areas in which compressed air systems are used. The finding and elimination of leaks in compressed air systems alone can save up to 35 % of the energy costs associated with the use of a compressor.

Leaks are caused by fluid flowing from a high pressure environment to a low pressure environment, creating turbulence. The turbulence generates high frequency sounds (so called ultrasound) which is inaudible by human hearing. LD 400 transforms these ultrasounds into an audible frequency which can be heard from several meters by using the supplied noise isolated headset. In unpressurized systems an ultrasonic tone generator can be used whose sound will leak through small openings.

Leak Detector LD 400

The ultrasonic leak detector LD 400 is designed for a quick and precise location of leaks in compressed air, inert gas and vacuum systems. System leaks can easily be detected.

  • Robustness and lightweight ensure a fatigue-proof use in industrial environments
  • Improved detection of leaks with optional acoustic trumpet
  • Modern lithium-ion battery with high capacity, external recharger
  • Minimum operating time 10 hours
  • User friendly and easy to use via keypad, no special training required
  • Integrated with laser pointer helps to spot the leaks from several meters
Working frequency 40 kHz  +2kHz
Connection  3.5 mm stereo jack for headset
Power supply socket for connecting a external charger 
Laser Wave length: 645…600 nm
Output power : < 1nW (Laser Class 2) 
Operation duration 10 hours
Charging time Approx.. 1.5 hours
Storage temperature -10 oC to 50 oC
Weight 0.4 kg, complete set in the case 2.8 kg
Case dimensions 263 x 96 x 88 mm 

LD 400 set in a case

The set includes a robust impact-proof transportation case which contains all necessary components and accessories.

LD 400 Set consisting of:

  • LD 400 Leak detector
  • Transport case
  • Sound-proof headset
  • Focus tube with focus tip
  • Battery charger
  • Acoustic trumpet


  • Compressed air and gases piping networks
  • Vacuum system
  • Steam traps
  • Refrigerant Leaks
  • Locating worn bearings
  • Leaks in pneumatic control systems
  • Leaks in natural gas, LPG leaks
  • Leaks in vacuum systems
  • Butane / propane storage tank leaks

Moreover, LD 400 is not only applied to compressed air, it also applicable to other gases including steam, refrigerant, nitrogen, oxygen, argon, hydrogen, natural gas, LPG … and more.

Vacuum Leak Detection

Vacuum leaks (sometimes referred to as ingress leaks) are common place in many industries from power generation to food processing. Condensers, distillation columns, freeze driers and turbines are all prone to leakage, and even small and seemingly innocuous leaks can affect efficiency, product quality, safety and uptime.

These "negative pressure" leaks are often notoriously difficult to locate, and engineers

without the appropriate test equipment may need to completely dismantle complex machinery in an effort to identify the location of a leak.


We detect large vacuum leaks by using a portable ultrasonic detector that works by listening for ultrasound created by turbulence as air is drawn in through a hole by the vacuum. Since ultrasound is above the human hearing range, the equipment can be used while the plant is in full operation, which prevents disruption to production and processes.

After detecting (and repairing) these larger leaks using the airbourne scanning module, a Close Focus Module accessory is available to boost the low-level leak detection capabilities of the equipment, which helps to pinpoint smaller leaks. These inspection techniques are completely non-invasive and can even produce very good results in complex installations and noisy plant environments.


Steam Leak

Steam systems are often one of the most important but overlooked systems in the plant. Wasted steam is far too expensive today to ignore. Early leak detection and maintenance of your system and components can save you resources and money.

Our audits include ultrasonic testing along with tagging of all failed traps in your system. We listen to trap cycles to determine if the trap is failed.

After the audit is finished, a report is generated to aid customers in repairing faulty traps.

It is not uncommon for 20% of traps to be found failed. Therefore the energy cost savings from repaired failed traps far exceed the cost of the steam trap audit. Steam is a high-value commodity; the higher the pressure, the higher the value so it is important to make every effort to repair your own steam leaks when they occur.

Not only do steam leaks cost energy and waste money, they waste boiler water and chemicals as well.

Steam traps can fail in an open or closed position. A trap that "fails open" allows steam to escape in to the condensate system. Traps that "fail closed" prevent condensate from being discharged, which slowly turns to carbonic acid and corrodes the metal.

A faulty steam trap is unfortunately not always easy to notice and typically leads to operational problems, safety hazards and wasted energy, and a single leaking trap is estimated to cost hundreds or thousands of dollars per year.