Product Specification

LLE Series Liquid Level Sensors Description

The enhanced series of liquid level sensors incorporates a photo-transistor trigger which provides a digital output that denotes the presence or absence of liquid.

The mode of operation is derived from the principle of total internal reflection. An LED and photo-transistor are housed within a plastic dome at the head of the device. When no liquid is present, light from the LED is internally reflected from the dome to the photo-transistor. When liquid covers 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 very fast, and almost instantaneous for water.

LLE Series Liquid Level Sensors Features

? Solid state technology
? Small size
? Digital output
? Pre-wired
? Electrically robust

LLE Series Liquid Level Sensors Benefits
? Accurate, repeatable switching point
? Can be mounted in applications where space is limited
? Microprocessor compatible
? Easy to install, saving assembly time
? Reverse polarity, over voltage, short circuit and transient protection

LLE Series Liquid Level Sensors Typical Applications
? Home appliances
? Spa baths
? Vending machines
? Food and beverage
? Medical
? Compressors
? Machine tools
? Automotive

LLE Series Liquid Level Sensors Order Guide

		Catalogue Listing
Description		Standard temperature	High temperature
Screw In, M12 Thread, Plastic	(Type 1)	LLE101000	LLE101101
	(Type 2)	LLE102000	LLE102101
	(Type 3)	LLE103000	LLE103101
Plus In, Plastic	(Type 5)	LLE105000	LLE105100
Screw In,? In, Plastic	Nickel plated brass	LLE205000	LLE205100
	Stainless Steel	LLE305000	LLE305100

LLE Series Liquid Level Sensors Technical Specifications

Specifications
Operation mode	User defined single point on/off switch (Output is high in air)
Repeatability (mm)	±1
Hysteresis (mm)	2 (dependent on liquid)
Response time	Rising liquid level - 50 μs Falling liquid level - 1 s max (in ethanol) Response in other liquids dependent on viscosity
Mechanical
Mounting	Type 1 and 2 - mounted from outside; Type 3 and 5 - mounted from inside
Termination	250 mm flying leads (180 mm for metal versions)
	Blue  0 V
	Red  +5 V  to +12 V supply
	Green  Output
Material [Note 1]	Polysulphone
Dimensions Dome   Thread   Hex	Plastic LLE101/102/103 Series	Metal LLE205/305 Series
	3,5 mm radius (includes LLE105 Series)
	M12x1	? BSPT
	19 mm	24 mm
Environmental	Standard temperature	High temperature
Operating temperature (°C)	-25 to 80 (-13°F to 176°F)	-40 to 125 (-40°F to 257°F)
Storage temperature (°C)	-30 to 85 (-22°F to 185°F)	-40 to 125 (-40°F to 257°F)
Thermal testing	As per BS EN60068-2-33
Humidity	As per BS EN60068-2-30
Vibration	As per BS EN60068-2-6 Part S3: 1996
Mechanical shock	As per BS EN60068-2-27 Part 2 Ea: 1987
Pressure range (bar)	0 to 5 (plastic housing) [Note 2] 0 to 25 (metal housing)
Ambient IR light limit (@ 940 nm) [Note 3]	10 mW/cm in operation
Electrical	Standard temperature	High temperature
Supply voltage (Vcc)	+5 Vdc to +12 Vdc ± 5 %
Supply current (mA)	15 mA nominal @ +5 Vdc	5 mA nominal @ +5 Vdc
Output sink current [Note 4] @ 5 Vdc supply	@ 25°C 10 mA max.	@ 25°C 40 mA max.
	@ 80°C 3 mA max.	@ 125°C 7 mA max.

Notes:
[Note 1] Material compatibility information available on request.
[Note 2] Threaded sensors only.
[Note 3] For other ambient light environments the user should test the sensor under application conditions to verify compatibility.
[Note 4] The output is intended as a TTL compatible output signal, for interfacing to logic systems. For interfacing with other types of circuitry an appropriate buffer circuit must be used.