Seiko DH33 Manual - Page 7

English HOW TO USE DIVE COMPUTER FUNCTIONS ■ NITROX DIVING FUNCTION ● The percentage of oxygen in the air used for ordinary diving is 21%. The higher percentage of oxygen in the gas mixture means a lower percentage of nitrogen than ordinary air, reducing the risk of decompression sickness. WARNING ● This function should be used only when you dive with a gas mixture of oxygen and nitrogen other than ordinary air. When diving with air, be sure to set the percentage of oxygen (FO2) to "Air". ● Never use the watch for diving with any value other than the actual percentage of oxygen in your tank set for FO2. ● If you have set FO2 for nitrox diving, be sure to re-check the FO2 setting before a dive. On the day following the day you made a nitrox dive, "- -" is displayed in place of the FO2 setting, "Nx" flashes, and the watch cannot be used for diving. In that case, set FO2 again. ● By setting "Air" for FO2, the percentage of oxygen is set to 21% as in the ordinary air. FO2 can be set from 22% to 50% according to the gas mixture of your scuba tank. ● When a value between 22 and 50 is set for FO2, the nitrox mark "Nx" appears on the display, and the watch is shifted for nitrox diving. ● The watch calculates the no-decompression limit, residual nitrogen and other data according to the FO2 you have set. HOW TO SET FO2 Press to show FO2 display. ▼ Press to show FO2 SETTING display. * For diving with ordinary air, set "Air" for FO2. Percentage of oxygen "Air": 21% for diving with ordinary air 12 ▼ ▼ or Press to set FO2. Nitrox mark • "+" and "-" appear near buttons C and D, respectively. * With each press of buttons C and D, the percentage is increased and decreased in increments of 1%, respectively. The digits move quickly by keeping the respective buttons pressed. * If a value between 22% and 50% is set for FO2, the nitrox ▼ mark "Nx" appears on the display. Press to return to FO2 display. English HOW TO USE DIVE COMPUTER FUNCTIONS Notes: 1. For 10 minutes after a dive, FO2 setting cannot be made. 2. If the watch is left untouched in the FO2 SETTING display, the display will automatically return to the FO2 in 1 to 2 minutes. When the nitrox mark "Nx" is flashing: Nitrox mark ● If FO2 was set for nitrox diving the previous day and the date has changed to the next, a flashing "Nx" is shown on the display. In that case, be sure to set FO2 newly before the next dive according to the gas mixture of your scuba tanks. ● How to re-set FO2 Press to show FO2 display. ▼ Press to show FO2 SETTING display. ▼ Press once to show "Air" for diving with ordinary air. • "Nx" disappears. ▼ or ▼ Press to set FO2 if you wish to dive with nitrox. Press to return to FO2 display. ▼ 13