
Installation instructions for LLE Series
Liquid level sensors
Sensing and Control
PK XP-4059
Issue 1
WARNING
PERSONAL INJURY
•
DO NOT USE these products as safety or emer-
gency stop devices, or in any other application
where failure of the product could result in personal
injury.
Failure to comply with these instructions could
result in death or serious injury.
General description
The LLE Series liquid level sensor provides a single point
detection via a TTL compatible output. When liquid is
present on the surface of the sensor the output sinks up
to a maximum of 10 mA.
LED and phototransistor chips are sealed into the base of
the plastic dome, in such a position that light is totally
internally reflected from the dome boundary to the
phototransistor. Thus the output is normally high. When
liquid covers the dome, the change in refractive index at
the boundary means light escapes into the liquid, so less
light reaches the phototransistor which thus causes the
output to switch low.
Cleaning
Proper fluids should be selected based on type of
contaminant to be removed. Honeywell recommends
freon and alcohol based solvents. Do not use chlorinated
solvents such as trichlorethane as these are likely to
attack the sensor material.
Liquid media compatibility
Before use check that the fluid in which you wish to use
these devices is compatible with polysulphone.
Electrical specifications
Supply voltage (Vcc)
-25 °C to 80 °C (-13 °F to 176 °F)
5 V ± 5 %
LED (Vf)
@ 25 °C (77 °F)
1.2 V @ 10 mA typ.
Supply current
@ 25 °C (77 °F)
15 mA nominal
Output sink current (Io)
@ 25 °C (77 °F)
10 mA max.
@ 80 °C (176 °F)
3 mA max.
Operating temperature
-25 °C to 80 °C
-13 °F to 176 °F
Storage temperature
-30 °C to 85 °C
-22 °F to 185 °F
Electrical diagram
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Vcc
RED
OUTPUT
GREEN
SCHMITT
TRIGGER
PHOTO
TRANSISTOR
0 V
BLUE
IRED
VOLTAGE
REGULATOR
CAUTION
•
Do not exceed maximum supply voltage.
•
Although the sensor is protected against supply
reversal, it is not recommended.
•
Do not overtighten screw-in type.
•
Do not use chlorinated solvents.
•
Do not mount with dome pointing downwards.
Failure to comply with these instructions may result
in product damage.