f. Ensure that SSR number 0 comes on if there is no ready light.
g. Make a selection (unwrapped), set sterilizer time for one minute, and set the
preset to 112C.
h. Close the door (SSR number 8 led is on).
i. Lock the door (SSR numbers 6 and 7 leds are now on). Check the
door-unsealed light on the control display to ensure that it is off.
j. Push the cycle start switch and then follow the cycle graph for the proper
You can only check SSRs if the control panel is opened.
Section III. CALIBRATION/VERIFICATION AND ADJUSTMENTS
In the previous section, you learned to verify that the sterilizer is operating
according to a known standard. Now you will learn how to calibrate/verify the sterilizer
when the unit deviates from the known standard. If the unit fails calibration, you must
repair it before returning it to service. A properly calibrated sterilizer is essential to
ensure its safe use during surgery. Perform the following procedures to calibrate/verify
a. Calibrate the Chamber and Jacket Temperature. The temperature signal
for the chamber and jacket is developed by the thermistors, 1-RTD and 2-RTD. The
voltage at the thermistors changes as the temperature changes and is changed to a
binary number by U-16, the Analog to Digital Convertor (adc). Calibration performed by
replacing the thermistors with a specific resistor value. This specific resistor value
represents a specific temperature and should produce a known DC voltage. Changing
the ZERO and SPAN adjustable resistors will cause the correct voltage to appear at the
input to the Analog to Digital Convertor. The ZERO and SPAN adjustments are
interactive. Changing one has an effect on the other. The adjustments are made back
and forth until no more change is noted, and the voltages measured are stable. The
thermistors will be replaced with resistors located in the RTD Test Box. Switches in the
RTD Test Box will select which thermistor channel to calibrate.
Perform a reference voltage check.
(a) Press controls on switch on the display board.
(b) Note that the 14 pin male DIP connector from the RTD Test Box is
connected to the J1 female DIP connector on the upper left corner of the control board.