Nov 20 2010
Macro Sensors has launched LVDT spring loaded position sensing devices called gaging probes, which functions as integrated elements in a control system and facilitate the precise landing of elevator cars in building floors.
When the speed of the elevator reaches 2,000 ft/min as the passengers travel on it, the sensors will furnish necessary information to the electromechanical control systems for executing accurate arrangement of elevator cars during their arrival at building floors.
LVDT Position Sensors
The elevator cars are loaded with springs across their periphery to deliver an easy and comfortable ride and in turn supplies cushioning action against the acceleration/deceleration effects and against the starting and stopping jerks occurring due to inertia. Due to passenger load on the elevator, the springs will compress to adjust the position of the car within the frame, to position the car at the desired floor.
The spring suspended LVDT positioning devices calculate the deviations between the car and the frame position and finally assures that the cars and building floors are accurately arranged during its arrival. The sensors will particularly monitor the spring deflection, due to passenger load.
The sensors can be integrated above or beneath the elevator car. If the calibration is executed from above, the LVDT position sensor will be compressed and extended depending on the load increase. If the sensors are integrated beneath the elevator car, the probe will normally elongate and compress based on the load applied. The final readings are logged into a control system which utilizes the displacement data to balance the travel of the frame, so that upon opening the elevator car doors, the car floor is adjusted with the building floor on which passengers are present.
Optional metric measurement systems are also available with Macro Sensors for supporting most of the spring-suspended LVDT positioning devices.
Source: http://www.macrosensors.com