Dive Rite introduced oxygen tracking on a dive computer in 1992 with the launch of the Bridge, the first user programmable computer from 21% to 50%. It has since become the standard for any Nitrox computer. Oxygen tracking was developed by Randy Bohrer and the late Dr. Bill Hamilton for SEIKO EPSON. SEIKO EPSON went on to patent the technology of graphing oxygen tracking on dive computers, but decided it was too important not to be on all dive computers to enforce the patent. This led to the birth of the OLI (oxygen limits index), which was based on hyperbaric treatment studies. See this article for more information: A PROVISIONAL METHOD OF OXYGEN EXPOSURE MANAGEMENT FOR A RECREATIONAL DIVE COMPUTER
In the oxygen tracking algorithm, we don’t track OTUs at all. Hamilton’s OTU approach was used to manage long exposures, such as saturation type dives. For the dive computers, we track one value – the oxygen limit index. This index accounts for both CNS and chronic/whole body oxygen toxicity (or oxygen tolerance). The 90 minute half time for recovery is very conservative for CNS toxicity, since we know that it is possible to breathe oxygen at high partial pressures if a short air break is taken periodically. It is adequate for chronic/whole body toxicity, since it allows for full recovery in an amount of time that is sometimes used in respiratory therapy.
The Nitek Q has nine bars for tracking oxygen and nitrogen. At 80% of calculated maximum oxygen exposure the bar graph will start to flash once the 8th bar starts to fill up. The Nitek Q will assume oxygen loading for one hour after the dive. This is our conservative approach to oxygen tracking. With a 90 minute half life, the 8 bars lit will drop to 4 in 90 minutes, then drop to 2 bars in another 90 minutes, and to 1 bar in another 90 minutes. If your oxygen loading exceeds 100% the graph will flash until it is back into range.
Remember, tracking is only as good as the information supplied. Properly analyzing and entering the correct gas mixture is a good start.
Pictured: Dive Rite technical computers starting with the Bridge II through Nitek Q
The latest release of the WB 3.0.2 is on the web. This release was designed to push firmware updates to your Nitek Q computer. If you purchased one before firmware 2.0 (black USB cap), then you haven’t been able to use the WB logbook function. If you purchased a later model (red USB cap), then you have access to the WB.
The WB is a free download from our website, and I encourage you to download it and update the firmware on your computer. We are up to version 2.0.5 on the firmware. The update includes better animation during battery charging and a 10 hour countdown on battery life. It still checks voltage, but now has a 10 hour countdown on the time the display is active. Since the display has the highest power consumption, it gives you a better indicator of battery life with a reserve. The overall battery life hasn’t changed.
To use WB 3.0.2 on a PC, it needs to have Windows 7 or newer and you need to have administrator rights. Everyone believes they have administrator rights to their PC, but sometimes the wrong check box or another program can change it. One user that was having issues with installation and communications to load the program used this link http://www.mytechguide.org/106/how-to-log-on-as-administrator-in-windows-7/ to log on as administrator, and it worked for him.
MAC is easier, but I had an issue with a USB port not allowing enough communications/power to allow for the re-flash, but would still allow me to upload dives. I switched ports and now everything works.
Since the program is internet based you must have a high speed connection to install the program or get any firmware updates or upgrades. Look for more features now that we can push firmware updates to your Nitek Q.
To download Workbench for Mac or PC visit: http://www.diverite.com/products/catalog/computers/co-xxxx
The rechargeable Li ion battery in the NiTek Q computer is rated for 300 charges from a deep discharge state. The computer has a sophisticated charging circuit to get the longest life possible from the battery. The key to long battery life is keep the battery topped off and avoid taking it into deep discharge. So don’t try to see how many dives you can get on a charge, keep the NiTek Q charged up for long battery life. It can stay on the charger indefinitely and it will hold a charge for up to six months.