TOKYO GAS TOP > Technical development > Toward the safe and secure supply of energy > Underground pipe exploration equipment

Underground pipe exploration equipment: "Tansa-kun" and an "Acoustic Vibration-type Survey Device"

Our equipment can explore the location and depth of buried gas pipes with unknown locations without excavation.



In some cases, due to town redemarcation projects etc., the actual location of buried piping becomes unknown, with locations differing from those in original drawings. The equipment searches for buried gas pipes with unknown locations without excavation. We have two types of equipment: the electromagnetic locator, called Tansa-kun, and our acoustic probe. Tansa-kun detects buried pipes by sending a flow of electric current through the pipes to detect a generated magnetic field. The acoustic probe transmits acoustic vibrations through the pipes to detect transmitted vibrational waves.




  • The possibility for 5 kinds of exploration with the complex-type detector, and detectors for disused piping and supply piping
  • With the output current automatic control method, equipment can measure depths of buried piping for a wide range of soil.
  • High precision, high-sensitivity, and high-stability are realized through the utilization of the crystal control method.
  • The ground bar with a display and transmitter enables prompt display of the confirmation of electric circuits.
  • An extendable detector, for improved work efficiency for interior piping.

An outline of our equipment

1.Types of equipment

(1)A set of underground piping exploration equipment

A picture of exploration equipment set
(2)Exploration for nail penetration in pipes (OP)

(3)Ceramic pipe remote exploration (OP)

(4)Road markers (OP)

(5)Disused piping and supply piping exploration (OP)


2.Tansa-kun construction case example
one- and two-point method exploration construction case examples


  • Pressure: not specified
  • Kinds of pipe: electrically conductive pipes such as cast-iron and steel pipes, etc.
  • Bore diameter: not specified
  • Depth: 3m
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Acoustic vibration type exploration equipment


  • Capable of searching all kinds of pipes with a variety of bore diameters regardless of electric performance.
  • No need for temporary road wiring to formulate circuits.
  • Has the propagation capability of transmitting sound wave vibrations from a single source for distances of 200m, 100m each to both sides to left and to right. Exploration for the total length is possible.
  • Exploration speed is significantly improved with the possibility to use a multiple pieces of receiving equipment for a single source for the transmission of sound wave vibrations.
  • In addition to pipeline piping, piping under interior floors and inside walls can also be searched.

An outline of our equipment

1. Exploration equipment set
Exploration equipment composition and a picture of an equipment set

2. Acoustic vibration type exploration construction case example
A picture of a construction case example and a figure indicating principles


  • Pressure: low pressure
  • Kinds of pipes: not specified; all kinds of pipes
  • Bore diameter: 20mm to 300mm
  • Depth: cannot be measured

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