Lid sensor and retrofit system

摘要

A non-contact lid sensor is provided for use with an oil field thief hatch and a latch. The sensor is mounted to the latch and comprises a reed switch. The latch pin is removed and embedded with a magnet with the magnet's north-south poles parallel to the pin's length so that the magnet triggers the reed switch. The reed switch is oriented so that it is perpendicular to the lower latch pin and the face of the sensor. The magnet and reed switch are aligned so that when the lid is closed the reed switch never sees the 0 Gauss line of the magnet. When the latch is in a closed position the reed switch allows the current to pass through the sensor and signal that the hatch is closed. The sensor system also allows for a Hall effect sensor to be used.

主权项

1. A method for sensing closure of a latch to a hatch lid, the method comprising:
mounting a sensor in the latch, the sensor having a housing and a front face; inserting a pin in the lid, the pin containing a magnet having a magnetization and wherein the magnet is oriented with its poles parallel to a longitudinal axis of the pin; wherein the sensor is positioned within the latch such that the front face of the sensor is juxtaposed to the pin; closing the lid; engaging the latch to the pin, whereby proximity of the sensor to the magnet indicates closure of the hatch lid, and communicating closure of the hatch lid by the sensor.