Operation Manual

FO2 MODE

After Activation, the XR2 will operate as an AIR computer without

displaying information associated with oxygen calculations, unless

it is set for a percentage of oxygen (FO2) other than AIR (numeri-

cal value between 21 and 50 %).

NOTE: Setting FO2 is described on Page 27.

When set with an FO2 value of AIR (Fig. 9), the XR2 will per-

form calculations the same as if FO2 were set for 21% oxygen, in-

ternally accounting for oxygen loading for any subsequent Nitrox

dives. However, oxygen related displays, warnings, and the O2 bar

graph will not appear on the display for that dive, or subsequent

dives, unless FO2 is set for a numerical value (21 to 50).

Once a dive is made with the unit set as a nitrox computer (FO2 set

for a numerical value), the unit cannot be programmed to operate

as an AIR computer until 24 hours after the last dive. AIR will not

be displayed as an option in the FO2 Mode. However, you can set

FO2 for 21% for use with AIR.

When FO2 is set at a value of 21% (Fig. 10), the unit will remain

set at 21% for subsequent nitrox dives until FO2 is set to a higher

value, or until it automatically turns off and is reactivated.

Fig. 9 - FO2 set for AIR

Fig. 10 - FO2 set for 21%