Nellcor OxiMax NPB-40 Service Manual page 26

Performance Verification
18
5. The current time is shown in a 24-hour format.
6. If the NPB-40 detects an internal problem during POST, an error tone sounds
and the NPB-40 shows an error code (Er) and the corresponding error number
(see Troubleshooting on page 33).
7. Upon successful completion of the POST, the NPB-40 sounds a one-second
tone indicating that the NPB-40 has passed the test.
WARNING: If you do not hear the POST pass tone, do not use the NPB-40.
WARNING: Ensure that the speaker is clear of any obstructions and that the
speaker holes are not covered. Failure to do so could result in an inaudible
alarm tone.
Note: In addition to serving as the POST pass verification, the POST pass tone
also functions as an audible confirmation that the speaker is performing
properly. If the speaker does not function, the alarm warning sounds cannot
be heard.