Patent ID: 7207211

Claim:
A method for controlling a process including polymer particulate, the method comprising contacting a mechanical resonator with polymer particulate in a chamber enclosing the polymer particulate, the mechanical resonator being a flexural resonator and being contacted with the polymer particulate in the presence of a flow of gas in the chamber, controlling one or more environmental conditions of the chamber, measuring the mass or mass change of the polymer particulate at a first time by applying an input signal to the mechanical resonator, monitoring a response of the mechanical resonator to the input signal, the response being represented by a response signal of the mechanical resonator, and processing the response signal to determine the mass or the mass change of the polymer particulate at the first time, varying one or more of the controlled environmental conditions in the chamber after the first time, and measuring the mass or mass change of the polymer particulate at a second time after varying the one or more of the controlled environmental conditions by applying an input signal to the mechanical resonator, monitoring a response of the mechanical resonator to the input signal, the response being represented by a response signal of the mechanical resonator, and processing the response signal to determine the mass or the mass change of the polymer particulate at the second time.