Bottled Liquid Checker


   --Necessity of simple and easy inspection method for bottled liquids at airports


In recent years, the level of incendiary attacks has increased. These crimes are often conducted by individuals bringing beverage containers filled with flammable liquids such as gasoline into densely populated public areas and setting them alight. The air transportation industry is particularly susceptible to such attacks. If flammable liquid is brought into an aircraft, a deadly terrorism event can easily occur. Therefore, it is extremely important to establish and develop methods to prevent such events.

Challenges against the conventional manual inspection

  • Difficulties to cope with the situation during peak check-in period (since containers must be uncapped one by one, the procedure takes time and creates a long passenger queue).
  • Passenger inconvenience (waiting for each container to be opened and checked for smell or having the passenger drink the contents, which is very unpleasant).
  • Possibility of human error (time pressures security staff to perform cursory checks only). This tends to overlook the suspected flammable substances.
  • Risk of security operators getting infected by germs or virus.

Design Philosophy

POINT 1: Through put

Typical airport security gate at busy hours has about 200 persons/hr/gate throughput

= 18 seconds/person/gate

(for X-ray, metal detector and Liquid Checker)

Very quick and simple inspection is required without opening the cap of bottles.


POINT2: Trade-off

Generally speaking, there is a trade-off between amount of information and inspection time. If abundant inspection time is allowed, more information including material identification can be obtained. The figure below schematically indicates the relationship. If a high through put is necessary, on the other hand, it is not realistic to obtain a lot of information.



Our solution: Two-step screening

Our solution to the challenges is to design a bottled checker as a rough screening device with low false alarm rate and short processing time; other inspection technique,which requires more processing time, should be used when suspicious material is found. Total through put is virtually not influenced by the secondary means because almost all the bottles to be checked are safe material, anyway.




Features of the Device

To meet the requirements of simple and easy inspection, Tokyo Gas developed the Bottled Liquid Checker. The device can judge within a few seconds whether the liquid in a PET, glass or aluminum bottle is flammable or not without sampling the contents of the container.

Advantages of the Product

  • Inspection is possible without uncapping the bottle. It takes only a few seconds for measurement, thus enables speedy inspection (very high throughput).
  • The inspection method causes no harm to human health.
  • This device has no moving parts, thus requires almost no routine maintenance.
  • The device reduces the need for human judgment significantly.
  • Compact in design and easy to use.
  • It is safer/healthier for the security staff to be able to inspect containers without opening them.

Situation in Japan

As of January 2006, 250 units of Liquid Checkers have been deployed at 61 airports in Japan. Following figure shows the number of our devices, which has been installed at major Japanese airports.



We have received reports from security personnel at airports where our devices have been installed that passengers are very cooperative and that each device is working smoothly and has reduced passenger's waiting times at security gates.



© 2005 TOKYO GAS ENGINEERING SOLUTIONS CORP. all rights reserved.