3. What is the best procedure to use to spin an MAS rotor to avoid problems?
There are normally instructions in the user manual for the correct method for your probe. However, some general instructions are:
• Start with about 10 psi of bearing gas pressure.
• Add a couple of psi of drive pressure to get the rotor spinning.
• Gradually increase bearing and drive together keeping bearing 10 to 15 psi higher than drive up to about 40 psi on the bearing.
• After this the drive can be increased faster than the bearing until the drive is equal to or slightly greater than the bearing up to the maximum spinning speed. This should be achievable with less than 60 psi on both drive and bearing gas lines.
• Regardless of the above instructions always listen carefully to the sound of the spinner. If there is a change in pitch quality, this may indicate that more bearing pressure is required.
The user should be aware that there are spinning speed limits that are different depending on the type of rotor, turbine cap and sample being used. Never exceed the speed rating of the slowest component in the spinner system. The speed ratings for various components are given in the user manual and on the MAS Spinning Speed Page .
