IEC 60601-1-8, difference between table 4 and annex D

Cecilie Krosby

we are developing a single use unit, which should have an audible alarm. We were told to follow IEC 60601-1-8 on audible alarms.

I don't understand how to read the Annex D, which has different parameters from table 4:
Table 4 states that the pulse frequency should be btween 150Hz to 1000 Hz and that there must be at least 4 harmonic components in the range of 300 Hz to 4000 Hz.
Annex D, in section D.2 States that: "The frequency range of an alarm signal should be between 200 Hz and 5000 Hz. The preferred range is between 500Hz and 3000 Hz."

Can anyone explain what directions I need to follow?


Inactive Registered Visitor
Table 4 is in the requirements section, which is mandatory.

Annex D is informative, and discusses some of the things that impact perceived urgency.

Section D.2 is just a generic comment on frequency ranges on alarm signals, in general. Also, please note that the mandatory requirement os Table 4 are under the generic range mentioned in Section D.2.
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