Tunel Guard

Stand-alone system designed to detect human moving within a tunel.

What’s ralen tunel guard?

Epofat Tunnel Guard (ETnlG) is a stand-alone system designed to detect any human moving within a tunnel made of steel reinforced concrete or other materials. The system uses a single vertically mounted sensor housed in an eight inch diameter protective durable PVC pipe that can be lowered down a bore-hole next to the SRC tunnel. The sensor is then connected to and powered from a surface control unit. Any human passing by the sensor within the tunnel will immediately be detected and an alarm indicated at the surface control unit. As for all Ralen Epofat products the technology employed is harmless for operators and detected individuals alike. The system will always detect the presence of any living human being but will ignore any animal signature such as rats, dogs, cats etc.
The sensor is operated from a control workstation situated on the surface in an appropriate booth or room. Alternatively all information can be relayed to another more suitable location for command and control purposes. All data from the sensor are stored centrally.

One box with dimensions 420x420x2500 mm includes:

  1. antenna - 1pc
  2. CCTV kamera - 2pcs
  3. sensitive directional microphones - 2pcs
  4. UPS - 1pc
  5. LAN switch (optional) - 1pc
  6. wireles router (optional) - 1pc
  7. Industry PC - 1pc
  8. circuit- breakers blocks for equipments, the electronic systems and software interconnecting cables and accessories - 1 block

The system operates from any AC mains supply providing 230 Volts. In case of a power failure the system is backed up with a UPS.

Technical specifications

Power supply

a. Low voltage 12-24 VDC from AC line at 120VAC,60Hz, 1A max.

b. Other forms of power supply, by battery, can be designed after consultation


IP 67

Operational conditions:

Temperature: -20°C to + 60°C

Humidity: 20% - 100%

Alarm indication


Signal output


Detector reference field frequency

135 kHz > 72 dB μA/m

Monitoring range

up to 6m radius (variable)


capacity monopole, impedance 50 Ω

Antenna radiation

-13 dBm (EN 50371)



Communication Interface

Protocol RS232/422 or 485

EU Standard

EN 300 330-1 v 1.3.1: 2001
EN 50 371
EN 50 357