Zero Speed Detector For Centrifuge

The centrifuges are rotating at high speeds. To avoid the danger due to untimely opening of the centrifuge door, zero speed detectors is used as a preventive/safety device.
when the centrifuge is rotating, solenoid is activated and the door remains closed even though someone tries to open it .the solenoid is de-activated when the centrifuge speed approaches to zero. I.e. Only when the centrifuge stops rotating.
inductive proximity switch is used as a sensor and is placed in close proximity of the rotating object. On this object, metallic plates are fixed. Proximity sensor detect presence of metal objects which come within the range of their oscillating field giving rise to corresponding pulses. These pulses are fed to the control unit where they are compared with the standard pulses to sense the speed. Output is in the form of relay contact.
special sensor as well as control is available for use in hazardous area. The enclosures and enclosures are certified by competent authority for use in gas group: iia, iib as well as iic