I inspected the oxygen gauge and opened the valve a trifle wider.

His oxygen gauge showed empty.

Except for the oxygen gauge, which stood at fifty minutes.

The oxygen gauge read below empty.

I thought about this a long time, keeping one eye on the oxygen gauge.

She glanced at the oxygen gauge prominently displayed on his tank.

"I can see my oxygen gauge."

She eyed her oxygen gauge.

She did not look at her oxygen gauge; if it went too low, too fast, there would be no helpful bomb disposal team to hook up a new one for her.

A movement in her helmet caught her attention-her suit's internal clock was working again, and the oxygen gauge squirted up, then dropped, then rose again slowly to indicate that she had 35 percent of her supply left, one hour and eighteen minutes at current usage.