4.2.3Mute Button
The mute button silences the humidifier's audible alarm. The muted time depends on the alarm condition. In general, alarms will be muted for 2 minutes.
A chamber or airway probe alarm is muted for a longer time, until the humidifier determines whether the probe is in or out. The temperature alarm is treated differently - see section 4.5.
4.3Temperature Display
The front panel shows the lower of the chamber or airway temperatures. This temperature gives an indication of the dew point (in °C) of the gas that is being supplied to the patient. The dew point of a gas is the best indication of both its humidity and energy content. Under normal operation, the displayed temperature will be the chamber temperature, as its control set point is lower. If the temperature is above 70 °C, "Hi" will be displayed. If the temperature is below 10 °C, "Lo" will be displayed. If HC mode has been enabled the decimal point on the temperature display will flash.
4.3.1Showing Chamber and Airway Temperature
Both the chamber and airway temperature can be displayed by pushing and holding the mute button for 1 second. The temperatures are displayed in the following sequence:
1Chamber temperature is displayed until two seconds after the mute button is released. The chamber probe indicator (see section 4.4) will also light to show which temperature is being displayed.
2The display will blank, and then the airway temperature will be displayed until two seconds after the mute button is released. The airway probe indicator will also light (see section 4.4) to show which temperature is being displayed.
3The temperature display will blank again, and revert to normal operation.
4.4Setup Indicators
The MR850 setup indicators, placed on the lower left of the front panel, are intended to aid the user in identifying problems with the incorrect setup of the device and its accessories.
4.4.1Heater wire connector
These indicators light if the heater wire in the breathing circuit has not been connected correctly, or if the heater wire or heater wire adaptor is faulty. An intermittent connection, or excessive current (total current in all limbs > 3.5 A) in the heater wires will also produce this alarm. The humidifier will remove power from the heating systems if this alarm is active.
NOTE: Software versions 5.45 and 5.70 do not light the upper indicator located on the breathing circuit.
NOTE: Software versions 7.22 and 7.23 in non heater wire operation and without a heater wire connected no audible or visual heater wire alarm will be given. Connecting a heated wire circuit will automatically cause the MR850 to default to heater wire operation.
MR850 Technical Manual * Revision J * Issued November 2005 * Ref. 185041340 (185041713 internal) | 17 |