Centrifuge overspeed protection and imbalance detection system

A system for the detection of high speed centrifuge rotor imbalance, comprising:

• means for sensing true rotor speed when said rotor is in balance and generating a rotor tach signal having a frequency proportional thereto;
• means for measuring the frequency of the rotor tach signal at a plurality of sampling intervals;
• means for generating a dynamic reference frequency, said dynamic reference frequency being a reference frequency derived according to expected rotor operating conditions when the rotor is in proper balance;
• said dynamic reference frequency changing with time as rotor speed and acceleration change;
• comparing means for comparing the frequency of the rotor tach signal sampled at each of a plurality of intervals to the dynamic reference frequency and deriving a deviation frequency;
• and
• means for processing the deviation frequency and determining whether said deviation frequency exceeds a predetermined range, whereby centrifuge rotor imbalance is detected when said deviation frequency exceeds said predetermined range.

In determining irregularities in the operation of said centrifuge, the steps of which comprise:

• deriving a tach signal during the operation of said centrifuge;
• determining the frequency of said tach signal during a plurality of discrete intervals;
• detecting any differences between any of the frequencies determined for each of the discrete intervals and an expected frequency;
• and, comparing said detected difference against a known standard thereby detecting the existence of irregularity in the operation of said high speed centrifuge.

In a centrifuge a system for the detection of rotor imbalance comprising:

• signal generating means for generating an electrical signal having a frequency indicative of actual rotor speed when the centrifuge rotor is in balance and which deviates therefrom when said rotor is out of balance;
• means for generating a reference signal having a frequency derived according to expected conditions when said rotor is in proper balance;
• comparison means for comparing the frequency of said electrical signal from said signal generting means with the frequency of said reference signal;
• and
• deviation signal generating means for generating an output signal when the frequency of said electrical signal deviates from the frequency of said reference signal by a predetermined amount whereby centrifuge rotor imbalance is detected and signalled.

A system for the detection of centrifuge rotor overspeed and imbalance comprising:

• signal generating means for generating an electrical signal having a characteristic indicative of acutal rotor speed when the centrifuge rotor is in balance and which deviates therefrom when said rotor is out of balance said electrical signal also having a characteristic identifying the particular rotor present;
• means receiving said electrical signal and generating an output indicating the maximum speed for the identified rotor;
• means for generating an output signal when said electrical signal indicates that the actual rotor speed has exceeded the maximum speed for said identified rotor;
• means for measuring the speed indicating characteristic of said electrical signal at a plurality of sampling intervals;
• means for generating a dynamic reference characteristic, said dynamic reference characteristic being a reference characteristic derived according to expected rotor operating conditions when said rotor is in proper balance, said dynamic reference characteristic changing with time as rotor speed and acceleration change;
• comparing means for comparing the characteristic of said electrical signal sampled at each of a plurality of intervals to the dynamic reference characteristic and deriving a deviation characteristic;
• and
• means for processing the deviation characteristic and determining whether said deviation characteristic exceeds a predetermined range and generating an output signal when said range is exceeded whereby centrifuge rotor imbalance is detected.