COMINOX STERILCLAVE 18 - Sterilisation Temperature Band Alarm: Overtemperature; Undertemperature; Temperature Adjustment

35
Sterilisation temperature band alarm: overtemperature
/ undertemperature
Both alarms indicate that the temperature is out of the sterilising band (tolerance) defined
by EN 13060. This standard defines the tolerance band (0°C - +4°C) from the setting value
during sterilization. For example, if the setting is 134°C, the temperature should be in the
band 134°C-138°C.
The steriliser may display one of these alarms during sterilisation when the temperature in
chamber 09 and/or the theoretic steam temperature are out of the tolerance band.
This alarm could be generated by incorrect temperature and pressure values.
• If the UNDERTEMPERATURE alarm appears, check that the load weight does not exceed
the maximum value allowed (see USE AND MAINTENANCE MANUAL, chapter
OPERATING USE).
• Check steriliser temperature and pressure.
Temperature adjustment
The temperature displayed must be 0.5°C lower than the actual temperature in chamber
09.
To adjust the temperature, firstly calibrate chamber temperature probe 39 in the
Technician Menu, options 3 (PT1 board calibration) and 7 (PT1 probe calibration).
If the temperature is still not correct, adjust the Correction parameter in the Technician
Menu (see step 1 and 2) or replace the sensor (step 3).
1. Using an external tool
- Remove the steriliser from the unit (if it is built-in) and remove the covering.
- Loosen and remove one of the inspection plugs 40 on chamber 09.
- Insert the probe of the external tool checking its tightness and place it in contact with the
end of chamber temperature probe 39. Alternatively, wireless probes may be used. These
are introduced into the sterilising chamber and do not require assembly.
- Start an operating cycle and check the values. This operation should preferably be
performed with Cycle 134 HOLLOW/POROUS, because the pressure in this cycle is best
aligned to the saturated steam curve.
- Adjust the temperature using the Correction parameter in the Technical Menu (option
10).
2. Using a sample coil
- Switch off the steriliser using main switch 13 and disconnect chamber temperature probe
39 (connector CN12 on power board 34).
- Connect a sample coil with an R value from 1000 to 1573 Ohm, corresponding to a
temperature (°C) of
T = (-R0*A+(R0^2*A^2-4*R0^2*B+4*R0*R*B)^0,5)/2/R0/B
where
R0 = value of chamber temperature probe 39 at 0°C (written on label and set in PT1
probe calibration in the Technician Menu)
A = 0,0039083
B = -0,0000005775
- Switch on the steriliser and check the temperature value which appears on the display.
- Adjust the temperature using the Correction parameter in the Technical Menu (option
10).
Alarms