ppm
CO
Provided the subject is not too distressed after seeing the breath CO
measurement, then the calculated foetal carboxyhemaglobin level
may be displayed by pushing the slide switch to the top position
(FCOHb):
%
FCOHb
The unit must not be used, however, for one second after the unit is
first switched on i.e. before the display shows 'BLOW'. Expired
alveolar gas is then entrapped between sensor and mouthpiece
valve. The display reading will rise to a plateau over the course of
several seconds. The final value will be held until the unit is turned
off and represents parts per million CO or %FCOHb depending on
the slide switch position.
The lights will come on according to the table on
page 10.
Important note:
Before repeating a measurement the unit must be turned off,
and the mouthpiece and adapter removed for at least 1
minute. This is to allow re-equilibration with ambient air and
to dry the surface of the sensor. Visually inspect that all
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