Honeywell AIDC Honeywell AIDC LLE102101 Liquid Level Sensor

Honeywell's enhanced LLE series of liquid level sensors incorporates a photo-transistor trigger, which provides a digital output that denotes the presence or abscence of liquid.These sensors work on the principle of total internal reflection. Inside the plastic dome at the device's head, an LED and photo-transistor are housed. When no liquid is present, light from the LED is reflected internally from the dome to the photo-transistor. When liquid is covering the dome, the effective refractive index at the dome-liquid boundary changes, allowing some light from the LED to escape. Thus the amount of light received by the photo-transistor is reduced and the output switches, indicating the presence of liquid. This method of liquid level sensing is fast, and almost instantaneous for water.Typical applications· Home appliances· Spa baths· Vending machines· Food and beverage· Medical· Compressors· Machine tools· Automotive