Monitoring one or more objects using an optical fiber for changes in condition thereof

A method for monitoring a plurality of objects for changes in condition of each of the objects comprising:

• providing a plurality of sensors at spaced locations, each having a movable member responsive to a change in condition of a respective one of the objects to be monitored;
• providing an optical sensor fiber extending to each of the objects to be monitored;
• placing the plurality of sensors at said spaced locations in contact with said optical sensor fiber;
• using an OTDR processor in communication with said optical sensor fiber for transmitting an optical signal along said optical sensor fiber and for receiving therefrom signals reflected back on said optical sensor fiber including signals reflected back from each of said sensors;
• each of the sensors being arranged to receive at least part of the transmitted optical signal and to reflect back at least a part of the transmitted optical signal;
• the OTDR processor being arranged to generate an output which indicates and identifies receipt of a signal reflected back from each of the sensors;
• wherein the movable member of each respective sensor is arranged to change a level of reflectance of the respective sensor so as to change a proportion of the optical signal which is reflected back;
• wherein each of the objects is movable between first and second conditions;
• wherein the movable member of each respective sensor is arranged to change a level of reflectance of the respective sensor so as to change a proportion of the optical signal which is reflected from a high reflectance at the first condition to a low reflectance at the second condition;
• and wherein the output indicates and identifies that all of the sensors are in the first condition by receipt from each of the sensors of a high reflected signal at the high reflectance and indicates and identifies which of the of sensors are in the second condition by receipt from each of the sensors of a low reflected signal at the low reflectance such that the output visually shows which of the sensors are in the second condition.

A method for monitoring at least one object for changes in condition of said at least one object comprising:

• providing a sensor for said at least one object, the sensor including a movable member responsive to a change in condition of said at least one object to be monitored;
• providing an optical sensor fiber extending to said at least one object to be monitored;
• using an OTDR processor in communication with said optical sensor fiber for transmitting an optical signal along said optical sensor fiber and for receiving therefrom signals reflected back on said optical sensor fiber including signals reflected back from the sensor of said at least one object;
• the sensor of said at least one object being arranged to receive at least part of the transmitted optical signal and to reflect back at least a part of the transmitted optical signal;
• the OTDR processor being arranged to generate an output which indicates and identifies receipt of a reflected signal received from the sensors of said at least one object;
• wherein the movable member of the sensor of said at least one object is arranged to change a level of reflectance of the sensor so as to change a proportion of the optical signal which is reflected back;
• and wherein the output of the OTDR processor is arranged to indicate the change in the level of reflectance of the sensors of said at least one object;
• wherein the sensors of said at least one object is arranged to receive at least part of the transmitted optical signal and to reflect back at least a part of the transmitted optical signal received thereby by looping back to the optical sensor fiber said at least part of the signal received thereby;
• and wherein the signal reflected back from each of the sensor of said at least one object is changed by attenuating an amount of the signal which is looped back.

A method for monitoring at least one object for changes in condition of said at least one object comprising:

• providing a sensor for said at least one object, the sensor including a movable member responsive to a change in condition of said at least one object to be monitored;
• providing an optical sensor fiber extending to said at least one object to be monitored;
• using an OTDR processor in communication with said optical sensor fiber for transmitting an optical signal along said optical sensor fiber and for receiving therefrom signals reflected back on said optical sensor fiber including signals reflected back from the sensor of said at least one object;
• the sensor of said at least one object being arranged to receive at least part of the transmitted optical signal and to reflect back at least a part of the transmitted optical signal;
• the OTDR processor being arranged to generate an output which indicates and identifies receipt of a reflected signal received from the sensors of said at least one object;
• wherein the movable member of the sensor of said at least one object is arranged to change a level of reflectance of the sensor so as to change a proportion of the optical signal which is reflected back;
• and wherein the output of the OTDR processor is arranged to indicate the change in the level of reflectance of the sensors of said at least one object;
• wherein the sensors of said at least one object is arranged to receive at least part of the transmitted optical signal and to reflect back at least a part of the transmitted optical signal received thereby by transmitting the optical signal across a space between collimating lens arrangements and to change a level of reflectance of the sensor by attenuating the optical signals in the space.