Sentinel Expedition

The Sentinel Expedition LSS is the Worlds’ first rebreather qualified under EN 14143 as a life Support System that includes a quadruple[1] Co2 filter monitoring system and fully automatic activation. The patented technology used in the Sentinel LSS essentially eliminates the most common human failures associated with CCR accidents. It has the Worlds’ first and only gaseous CO2 monitoring system as well as the only *Hostile Environment Activation System—providing a level of confidence never before available.
*The HEAS automatically activates the LLS and informs the diver of any critical information or system requirements needed to support life.


                                     Sentinel Expedition                                                                         Sentinel Expedition with Travel Frame
 
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Key Features

1. An integral CO2 monitoring system displaying CO2 levels in millibar on the Primary display and providing warning alarms at 5 and 10mb. The life of the sensor is several years (dependant on use) and it is simply periodically calibrated in ambient air. An integral filter system is user changeable and spare filters are supplied with the system.
2. VGM incorporates a user changeable algorithm with ‘defaults’ which mimic common algorithms in use today and allow the user to further customize the system. VGM is the first algorithm capable of a multi-model approach tracking deep-water, mid-range and shallow decompression issues.
3. The off-board gas connection kit comprises two high quality Swagelok female connectors fitted to the gas blocks and two LP whips with male connectors for fitting to the off-board regulator first stages. The Sentinel Expedition off-board kit is the first to allow external gas to be routed both through the manual gas addition system and via the automation (solenoid/ADV).
4. Ballistic nylon breathing hoses covers are supplied to provide additional to the breathing hoses.
5. The Intelligent Secondary Display removes the calibration potentiometers from the electronics head and allows the backup PO2 system to be calibrated from the handset. This provides additional isolation for the backup PO2 system. In addition there is an option available to add a decompression algorithm (VGM) to the Secondary display so that it works as a backup dive computer.
6. The 5mm backplate is designed to evenly distribute weight when dry suit diving.
7. The software pack for the Expedition comes with additional software features such as VGM, alarm cancelling and an alternative dive display.

 With the different aspects of scuba diving in mind, the SENTINEL LSS range has been designed for military, commercial, scientific, professional and sports diving. This has been achieved with a no-compromise approach to LSS design, incorporating;

 Reliability and safety

 The system can be used even with the failure of main electronics

Using or military diving expertise, the systems have undergone a detailed Failure Mode Analysis (FMECA). This provides clear exposure of the interaction of failure scenarios. Outcomes of this analysis give feedback on potential high risk failure areas. All currently identified high risk areas have had design enhancements to achieve a higher level of robustness or an additional redundancy feature incorporated.

 Ease of maintenance

A no-tools approach has been the key criteria for routine maintenance functions.

The system is modular and breaks down into its component parts easily

 Simplicity of operation coupled with sophisticated alarms and monitoring

Once correctly configured the diver can simply breathe in and out while monitoring the automatic or manual addition of oxygen in the breathing loop.

The system advises the diver of any alarm conditions

The on-board decompression computer in the main electronics control system keeps track of the actual PO2 breathed by the diver. The integrated decompression algorithm is the same as used in the world standard VR decompression computers.

 Flexibility in operation and modularity

For specialist applications the system can be configured with different duration canisters, different display options, download options and gas types and even different counter-lungs[3].

 Redundancy in system failure solution scenarios

Wherever appropriate, a single failure of an electronic component will not cause failure of the complete system. The backup PO2 monitoring system will function even in case of a main electronics failure. Manual gas bypass systems can be used in conjunction with the backup PO2 monitoring. As an option on military and commercial systems, an external stainless steel depth transducer makes the unit suitable for saturation diving.

 Upgradeability

Units can have PIN upgrades to different software levels.

 Reprogram-ability

Units can be re-programmed to incorporate any changes to the software system.

For downloads, manuals, and more detailed information click here!   


Standard Sentinel
At VR Technology we realize that budget is often a concern for our customers. With that in mind it is possible to order a standard Sentinel LSS and upgrade the system as your budget allows. The standard Sentinel does not include the gaseous CO2 monitor, off board gas blocks, or breathing hose covers. It also comes with a standard backplate.

Sentinel Travel Frame

VR Technology has made travelling the world with your Sentinel and Sentinel Expedition LSS a breeze. This system is full of features that take the hassle out of dive travel:

• Easily remove and stow your electronics head and body in overhead luggage

• Use virtually any size cylinders available at dive destination

• Dive with any standard backplate, harness, and air cell

• Break down the rigid components of the Travel Frame to flat-pack

• Enjoy perfect trim/attitude

• Experience incredibly low Work of Breathing

  
Major components of the Travel Frame system:

Backplate

The backplate is a lightweight hard anodized aluminum plate designed to accommodate the following:

• The rebreather canister assembly cam bands

• Cylinder cam bands

• LP pipe-work tie-down points

• 1^st stage mounting posts

• The optional quick release cylinder clamps

 This backplate has 11 inch mounting points and is designed to be used with most standard fitting SCUBA backplate, harness and BCD’s. Users should ensure that their chosen harness/BCD combinations are compliant with the required CE regulations.

Using the cylinder cam bands or the optional quick release cylinder clamps, any tank size from can be mounted on the backplate.

Counterlung

The Travel Frame uses a single Over-the-Shoulder (OTS) counter-lung, which is attached to the rebreather harness using Velcro loops and webbing straps. The canister head quick-disconnect system of the standard counter-lung is kept to allow easy cleaning of the rebreather. This counter-lung is housed in a protective cordura bag and unique to the Travel Frame system. The standard Sentinel counter-lung inner should never be used with the Sentinel Travel Frame system.

Head-guard

The head-guard is a lightweight hard anodized aluminum cover which offers protection to the canister head of the rebreather. If required, the weight pockets from the standard sentinel rebreather case can be mounted on this head to adjust the in-water trim of the rebreather.

Foot

To reduce weight and any possible damage to surfaces the rebreather is on, the travel frame foot is machined from plastic. Mounting of the foot to the travel frame backplate is via two small Velcro loops; these loops create a ‘soft’ hinge and enable the diver to quickly change the canister absorbent without a full disassembly of the rebreather. This foot is held up by a webbing strap passed through the appropriate slots in the head-guard and the foot.

CE

VR Technology Limited declares that the Sentinel Travel Frame complies with the essential requirements of the following Directive(s):

• 2001/95/EC

• 89/686/EEC

When used in conjunction with the Sentinel & Sentinel Expedition rebreather, this product complies with EN 14143:2003.

OPTOCON

A Leap in Underwater Technology!

Since electrical systems have been used underwater, they have often been limited by the ability of interconnected devices to keep out water. In this respect, water getting into connectors and cables can be the main cause of system failures. With this overarching problem, VR Technology has devised an optical system called OPTOCON for interconnecting devices. This system is now used in our dive computer and life support products to increase the reliability of data communications underwater.

There are two basic optical systems employed in OPTOCON:

1. Polymer fiber optic cable to interconnect remote sensors that are not in line of sight – e.g. the HP sensors. The main advantage over electrical cable is that water flooding has no affect on either the connector or the cable.

2. Radiated Infra-red modulated transmission, for use in mainly internal system interconnections. No optical cable is required, reducing clutter and increasing reliability. This system is similar to that used in TV remote controls – hence a very reliable and error immune data link. In the Sentinel, this system is used for the PPO2 sensors and the TPM (Thermal Profile Monitor).

Both systems have batteries in the sending unit that can last around 3-5 years. Low power hibernate functions and intelligent transmission algorithms ensure reliable optical links and long battery life. Battery status as well as sensor status is transmitted to the host device, therefore battery replacement or module replacement can be done well in advance of critical battery levels.

The OPTOCON system achieves improved reliability when compared to cable and connector interconnected systems. As the data transmission is optically digital, the system can receive data even with poor transmission paths. System connection status accurately shows if there is a link or module fault. This gives improved data integrity compared to analogue electrically connected systems, whereby an unconnected or faulty cable/connector cannot be detected reliably except by inference or as an ‘unusual’ reading. The OPTOCON system status clearly shows faulty or missing modules, allowing the user to take appropriate action. Due to the encoding and error checking of the data streams, sunlight, TV remote controls and other extraneous light will not be interpreted as sensor data.

The Sentinel Expedition Life Support System ( LSS) now comes equipped with three OPTOCON sub-systems:

1. The HP pressure gas sensors

2. The oxygen sensors

3. The TPM array

The VRX and NheO3 computers also use the OPTOCON technology for their external systems:

1.  Remote cell sensing

2.  PC interface                                                                                     To upgrade your Sentinel to Optocon click here!

[1] Gaseous CO2, Thermal array, Metabolic rate timer and ‘worst case’ extreme rate timer

[2] HEAS is activated by either breathing the set or reaching a shallow depth or a manual turn-on.

[3]

Sentinel Travel Pack Option