Conventional photoelectric sensors for detecting PET bottles depend on refraction and the attenuation of light intensity caused by surface reflection. However, it is difficult to attain a sufficient level of excess gain with these methods. The E3ZM-B PET optimised models utilise the birefringent (double refraction) property of PET bottles to significantly increase the level of excess gain. The polarization component that is disturbed by the PET bottles as they pass along the line is cut by a special and unique Omron polarization filter. This greatly lowers the intensity of the received light level and provides enhanced stability compared to conventional sensors.

Enhanced detection stability with E3ZM-B using the double refraction property

Conventional PET detection sensor

The E3ZM-B PET optimised models use automatic light adjustment to compensate for soiling or temperature fluctuations. With conventional sensors, parameters may require resetting when the sensor or reflector becomes contaminated with dust or dirt. Temperature fluctuations may also lead to detection errors, as this can effect the performance of the LED. Original Omron light emission control technology greatly reduces the resetting work required.

The IP69k test according to DIN 40 050 part 9 is intended to simulate high pressure / steam cleaning. During the test 14-16 l/min water at 80ºC is sprayed onto the sensor from different angles with 8000-10000 kPa. The sensor may not suffer any damaging effects from high pressure water in appearance and functionality.

The detergent resistant sensors are tested on alkaline and acid based detergents commonly used in the food industry. In comparison to conventional metal or plastic housing sensors, longer sensor lifetimes of 20 times or more can be achieved.