
OPTEK reserves the right to make changes at any time in order to improve design and to supply the best product possible.
OPTEK Technology Inc. —
1645 Wallace Drive, Carrollton, Texas 75006
Phone: (972) 323-2200 or (800) 341-4747
FAX: (972) 323-2396 sensors@optekinc.com www.optekinc.com
Issue A.4 02/06
Page 1 of 4
Tube Liquid Sensor
OPB350 Series
Applications:
Non-contact fluid sensing
IV fluid
Oils and other petroleum products
Colored fluids
Toner fluids
Water
Ordering Information
Part Number
Package
LED Peak
Wavelength
Sensor
Tube
Size
Lead Length /
Spacing
OPB350
N
890 nm
Transistor
0.125"
0.330” / 0.320”
OPB350L187
0.187"
OPB350L250
0.250"
OPB350W187Z
0.187"
24" / 26 AWG Wire
OPB350W250Z
0.250"
T
Features:
Can identify if liquid is present in clear tubes that have an
outside diameter of 1/8" (3.2mm), 3/16" (4.8mm) or 1/4" (6.3mm)
Opaque plastic housing enhances ambient light rejection
Printed circuit board mounting or 24” (610 mm) wires
Description:
The
OPB350
series liquid sensor is designed to work with 1/8” (3.2mm), 3/16” (4.8mm) and 1/4” (6.3mm) outside
diameter clear tubes. When output reference circuitry is added, multiple output states such as “fluid present,” “no
fluid present” and “no tube present” can be recognized.
Clear liquid present causes the phototransistor to sink the maximum current, while dark liquid present causes it to
sink the minimum current. As bubbles pass through the tube, the signal will vary between the “l(fā)iquid present” and
“no liquid” states. If no liquid is present, the phototransistor sinks only a small amount of current. If no tube is
present, the phototransistor sinks a larger current than in the “no liquid” state.
Smaller outside diameter tubes can be used when the tube is sized up to one of the standard sizes and is fitted
properly in the housing opening. For example, fluid in a 1/16” (1.6mm) outside diameter tube can be sensed
when a piece of tubing with a 1/8” (3.2mm) outside diameter and a 1/16” (1.6mm) inside diameter is used as an
adapter.
Product Photo Here
Opto Switch
C
R
R
LM393
or
LM339
LM393
or
LM339
R
R
Vcc
Gnd
Vcc
Vth
Vth
Vth
Gnd
Vth
R
R
C
1
1
2
2
Output
Output
1
2
Typical Application Circuit
4
OPB350
“N”
Package
“T”
Package
RoHS