Figure 4.3 Temperature vs Time to Alarm

Pressing mute during a temperature alarm silences the alarm for half the normal time period, if the same temperature is maintained.

The low temperature warning and alarm can be caused by cold or drafty ambient conditions, or can result from using gas flow rates outside the specification of the breathing circuit, chamber or humidifier.

NOTE: The low temperature alarm is disabled in stand-by on software version

5.45and 5.70.

4.5.2Non-Heater Wire Operation (Software versions 7.22 & 7.23)

When the airway temperature exceeds 41 °C, the heater plate is shut off, and an immediate visible and audible high temperature alarm is activated.

In invasive mode, the low temperature warning and alarm is identical for the heater wire mode (see above) after warm-up.

In addition the airway temperature must reach 29.5 °C in invasive mode (or 26 °C for non-invasive mode) within 15 minutes, otherwise a visible and audible low temperature alarm will be given, and the heater plate will be switched off. This will occur if the airway probe has not been inserted into the breathing circuit.

After warm-up, if the airway temperature drops below 29.5 °C (or 26 °C non- invasive mode), a visible and audible low temperature alarm will be given, and the heater plate will be switched off.

NOTE: The low temperature alarm will be inactive in stand-by.

4.5.3See Manual Indicator

This indicates a serious hardware fault. Please refer to section 6, "Troubleshooting".

20 MR850 Technical Manual * Revision J * Issued November 2005 * Ref. 185041340 (185041713 internal)