The present invention relates generally to a sensing system for monitoring the state of a system of components, and in particular, to a sensing system for monitoring the state of a system of components and for providing a warning when the state of any component within the system of components requires attention.

An improved system and method of measuring the temperature of a workpiece being processed is disclosed. The temperature measurement system determines a temperature of a workpiece by measuring the amount of expansion in the workpiece due to thermal expansion. The amount of expansion may be measured using a number of different techniques. In certain embodiments, a light source and a light sensor are disposed on opposite sides of the workpiece. The total intensity of the signal received by the light sensor may be indicative of the dimension of the workpiece. In another embodiment, an optical micrometer may be used. In another embodiment, a light sensor may be used in conjunction with a separate device that measures the position of the workpiece.

An improved system and method of measuring the temperature of a workpiece being processed is disclosed. The temperature measurement system determines a temperature of a workpiece by measuring the amount of expansion in the workpiece due to thermal expansion. The amount of expansion may be measured using a number of different techniques. In certain embodiments, a light source and a light sensor are disposed on opposite sides of the workpiece. The total intensity of the signal received by the light sensor may be indicative of the dimension of the workpiece. In another embodiment, an optical micrometer may be used. In another embodiment, a light sensor may be used in conjunction with a separate device that measures the position of the workpiece.

A temperature indicator includes a micro-sensor having a sensing element with a first layer coupled to a second layer where the first and second layers have different coefficients of expansion. The sensing element is configured to move from a first position to a second position in response to exposure to a temperature event and has detection circuitry configured to change from a first state to a second state in response to movement of the sensing element to the second position. The detection circuitry is prevented from returning to the first state in response to changing to the second state. An RFID module is coupled to the detection circuitry and is configured to output a value indicating that the sensing element is in the second position. An activator element is configured to maintain the sensor element in the first position until removal of the activator element from the micro-sensor.