iCG - intelligent Contents Gauge


The Fathom Systems intelligent Contents Gauge (iCG) monitors the pressure of bell mounted emergency gas cylinders and transmits this information to the surface so that any gas loss is immediately detected. 

When they are in the water, saturation divers depend upon surface supplied breathing gas. If this fails, there is an automatic changeover to a bottled emergency gas supply carried on the bell.

If, for any reason, the emergency supply is depleted, safety factors are reduced and expensive downtime is incurred while the bell is recovered and the emergency gas bottles are recharged. In order to alleviate this, the iCG in either stand-alone mode with dedicated PC and monitoring software, or as an integral part of a Fathom DMS or iBIS, is the answer.


Increased Safety

There are a number of ways that the onboard breathing gas can be lost during diving operations, including inadvertent valve operation inside the bell, accidental disconnection of the surface supply, or gas leakage from high-pressure pipework.  Flowmeters on the emergency gas lines cannot detect all of these situations.  The only way to ensure that the gas supply is intact is to measure the amount of gas in the cylinders by monitoring bottle pressure.

The iCG measures three high-pressure heliox bottle pressures and one oxygen bottle pressure.  These measurements are transmitted to and displayed in the Dive Control room.  Audible and visual alarms alert the supervisor to any loss of pressure and allows appropriate remedial action to be taken.

No Lost Time or Reportable Incidents

Most diving contractors have experienced accidental loss of bell onboard gas at some time, which can lead to abandoned dives, reportable safety incidents and lost vessel time.

Fathom’s iCGs have been in service since 2007 and are known to have prevented accidental loss of emergency gas on numerous occasions.

Upgrades or New Systems

Fathom Systems have installed iCG systems on a variety of diving bells – ranging from new-build bells to upgrades of existing dive systems. iCG systems are fully compliant with certifying authority regulations (DNV, LROS, ABS).

      • Onboard gas pressure range (HeO2)
        350 Bars, helium tolerant pressure transducers
      • Onboard gas pressure range (O2)
        250 Bar, O2 clean transducer
      • Power supply
        24V DC +/-20%
      • Telemetry to surface
        RS485 via 1 x TSP (optional RS232 for iBIS or 4-20mA)
      • Depth rating                                                  
        1000 metres external
      • Dimensions
        250mm nominal height x 99mm diameter
      • Housing material
        316 stainless steel, brass fittings
      • Underwater electrical connector
        7-pin Souriau ‘Jupiter
      • Safety relief valve
        1 bar internal protection, 6000MSW external
      • Pressure pipe connections
        No.4 JIC (orifice fittings)
      • Weight
        3.3kg in air, 2.5kg in water

The iCG can be supplied as a stand-alone system consisting of a bell-mounted pod, topside touch-screen panel PC, topside interface unit and interface cables.  The topside interface unit contains an isolated RS485 driver and a power supply for the bell unit including a dedicated line insulation monitor.

Alternatively, the iCG can be incorporated into a Fathom Systems Diver Monitoring System (DMS), an intelligent Bell Instrumentation System (iBIS) or any other telemetry system.

The iCG may also be supplied with 4-20mA signal output Transducers fitted.

iCG Topside Electrical Interface Junction Box rotated

iCG Topside Electrical Interface Junction Box