Precautions During Use

Electromagnetic sensor Precautions During Use

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About external magnetism

Note that any object with residual magnetism in the detection area will affect the detection or the reset operation.

About magnetic metal

Note that magnetic metal (iron, nickel, etc.) present in the direction of the detection surface will affect the detection sensitivity.

About sources of magnetism

Check that the sensor operates correctly before using it if there are magnetism sources (motor, solenoid, etc.) in the surroundings of the electromagnetic sensor.

About the influence of surrounding metal

If there are magnetic objects with residual magnetism in the surroundings of the electromagnetic sensor, the detection distance will vary. Pay attention to the installation location and orientation of the sensor.

Two-wire type

  • Do not connect the sensor directly to the power supply without load. Otherwise, the internal circuits may be damaged.
  • When the electromagnetic sensor is On, the residual voltage Vs is generated by the internal impedance at both extremities of the two wires. Because of this, the voltage Vf applied to the load is lower than the power supply voltage by the amount of the residual voltage. Check that the load voltage is within the operating voltage range before using the sensor.
  • When the electromagnetic sensor is Off, very weak current (leakage current) flows in the circuit. Because of this, the voltage remaining in the load may cause the reset operation to malfunction. In such a case, connect a bleeder resistor in parallel to the load to decrease the voltage applied to the load to lower than the reset voltage.

About the electromagnetic sensor installation

If the sensor is installed on or near magnetic metal, the detection sensitivity may greatly vary. In such a case, keep a distance between the sensor and the magnetic metal greater than the distance between the sensor and the magnet tape. Check also carefully the detection characteristics before using the sensor.

About the operating environment

Avoid using or storing the sensors in locations subject to direct sunlight, with sudden temperature change, or where water, oil, chemicals, dust, or corrosive gases may contact the sensors.
Note also that the sensors lifespan and performance are greatly affected by condensation and frost.



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