How do I achieve wattages below 250W?
Full instructions on changing the wattage are in the section 'Wattage Adjustment/Calibration' of the manual. It is a straightforward procedure which gives the operator a good feel for the flexibility of the power output of the unit.
What is the function of the temperature probe?
In the past, before variable wattage and the development of the ColdSpot (a recirculated waterbed for the surface of the microwave cavity), sample temperature control was required from the temperature probe (known as setting a temperature restriction), otherwise the sample would in all likelihood overheat. The temperature probe does not report accurate temperatures in small fluid volumes (below 20mL). Due to this problem the protocol design for EM processing does not use the temperature probe, but variable wattage and the use of the ColdSpot ensure sample temperature control for the times and wattages given. The ColdSpot has a port to hold the temperature probe during microwave processing. Use the probe to check sample temperature after a processing step is completed and adjust time or wattage if you feel the sample temperature is too high or low. Resin polymerisation is controlled by the power output chosen (wattage) and the presence of the ColdSpot. Low wattage at the beginning ensures a slow temperature rise of the water. High wattage at the end produces the heat necessary to complete the polymerisation.
Do I need a water load?
No additional water load (beaker) is required and one should not be added when the ColdSpot is present.
How do I maintain ColdSpot temperature?
That is indirectly controlled automatically by the microwave circuitry. The ColdSpot will warm gradually with continuous microwave operation and will reach a maximum of approximately 50°C during the polymerisation process at high wattage. At much lower wattage the ColdSpot temperature will be at about 40°C.
What's the best sample holder to use?
The Prep-Eze can be used for all the processing steps: fixation, dehydration and resin infiltration. The holder can be cleaned easily with acetone following resin infiltration.