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Ref. 185040646 MR730/720/700/480 Technical Manual ¯ Revision F ¯ Issued March 2001
APPENDIX A___________________________________________________
A1 CALIBRATION MODE
Entry to the calibration mode is made by holding down the ‘Chamber Temp’ button and turning on the Mains Power
switch.
After a two second delay the display should show ‘-1-’.
On releasing the ‘Chamber Temp’ button the display will show the humidifier model number (730/720/700 or 480).
The ‘Chamber Temp’ button is now used to step between functions as shown below.
1 Model number display.
2 Software version display.
3 Traceability number.
4 41.0 °C comparator calibrate. VR4.
5 ADC zero calibrate. VR5.
On pushing the ‘Chamber Temp’ button the display will show the present function number then after a one second
delay step to the next higher function number, where if the ‘Chamber Temp’ button is then released then that function is
entered
The calibration mode will time out (to normal operating mode) 5 minutes after the last ‘Chamber Temp’ button push. The
normal exit mode is to turn the humidifier mains power switch off then on again.
For details on 41.0 °C and ADC zero calibration procedures refer § 5.3.
A2 ENGINEERING MENU
To enter the engineering menu push the Mute and ‘Chamber Temp’ buttons simultaneously and hold for at least 1.5
seconds. At this time the display will show SET (for set temperature display) as a pointer to that function and on release
of the ‘Chamber Temp’ button the display will show the set Temperature Control temperature setting to one decimal
place. To maintain this display, the Mute button should be kept depressed. If the Mute is released, the display will
revert to normal operation in about 6 seconds.
The display can be stepped through the engineering menu in two ways.
• If the Mute is held down constantly the functions can be selected sequentially by pressing the ‘Chamber
Temp’ until the display changes to the next function pointer, where if the ‘Chamber Temp’ button is then
released the display will show that function.
• Releasing the mute button the humidifier will automatically step through the menu until either the mute button
is pressed whereupon the display will show that function or if 6 seconds has elapsed and the humidifier will
display ‘End’.
If ‘End’ appears on the display and the Mute button is momentarily pushed the time out will be inhibited and the
stepping through the function pointers continued.
A2.1 ENGINEERING DISPLAY FUNCTIONS: HEATER WIRE MODE
SET Set temperature display (°C).
OFF Offset temperature display (Chamber Control) (°C).
Edc Heater wire duty cycle (%).
Cdc Heaterplate duty cycle (%).
hP Heaterplate temperature (°C).
L Programming link status.(L1, L2, ... L6).
CP Compare probes (Probe test).
Ei Heater wire integral.
Ti Heaterplate integral.