CAIRE HELiOS Marathon H850 Use Manual page 25

Caution
not stop within ten minutes after a fill, and excessive
visible frosting develops on the portable oxygen unit,
see Troubleshooting, page 41.
Note:
Immediately after filling, you may hear a slight hissing
sound from the portable oxygen unit. This is normal and
will stop after a few minutes.
9. Checking the oxygen contents
HELiOS Marathon
Using Your HELiOS Marathon H850 Portable Oxygen Unit
If the hissing sound from the portable oxygen unit does
indicator—Make sure the portable oxygen unit
is full. The amount of liquid oxygen contained in
the portable oxygen unit is measured by a built-
in internal scale. To operate the contents
indicator follow the listed steps.
a. Lift the portable oxygen unit by the contents
indicator strap.
b. Push the bottom backside of the portable oxygen
unit so that it is straight up and down.
TM
H850 Portable Oxygen Unit Home Use Guide 21