1. What do I check if my MAS probe will not spin up to specification?
The most common problem with spinning is poorly packed or balanced samples. Samples should be finely powdered to avoid more massive lumps positioned asymmetrically on the inside circumference of the rotor. Add the sample to the rotor as evenly as possible and then spin the sample slowly for a couple of minutes to let it “spin pack” before gradually increasing the speed.
Also fairly common with probes that have been in the field for a while is excessive turbine cap wear. Turbine caps wear both from spinning and handling during the loading process. The cap can be looked at under a magnifying glass to look for wear. It would be preferable to compare the cap to a new cap if you have one.
Much less common but still possible in some extremes is excessive rotor wear usually caused by spinning an unbalanced sample for a significant period of time. This usually also causes stator wear and may require a trip to the factory for service of the probe.
If you try to spin an empty rotor and still have problems with a new set of turbine caps then there may be a problem with the probe that will require factory service.
