No lens filter is attached.
The thermometer cannot identify
a secure position of the probe. An
accurate measurement was not
POS = position error
Ambient temperature is not within
the allowed operating range
(10 – 40 °C or 50 – 104 °F).
Temperature taken is not within
typical human temperature range
(34 – 42.2 °C or 93.2–108 °F).
HI = too high
LO = too low
System error – self-check display
flashes continuously and will not
be followed by the ready beep
and the ready symbol.
If error persists,
If error still persists,
Attach new, clean lens filter.
IRT 4020: Clear the display by
pushing the «start» button once.
IRT 4520: Clear the display by
pushing the «I/O» button once.
Take care that the positioning of
the probe is correct and remains
Allow the thermometer to remain
in a room for 30 minutes where
the temperature is between
10 and 40 °C or 50 and 104 °F.
Make sure a new, clean lens filter
is attached and thermometer is
properly inserted. Then, take a
Wait 1 minute until the thermo-
meter turns off automatically, then
turn on again.
... reset the thermometer by re-
moving the batteries and putting
them back in.
... have the thermometer checked
at a Braun Customer Service