Specifications are subject to change without notice (25.06.99)
1
Type: Refraction principle
Housing material
Tip material
Light source
Output type
Connection
Level Sensors
Product Description
Optical level probe with
modulated infrared light for
detection of liquids. Self-
contained unit has built-in
amplifier. Separate transmit-
ting and receiving elements
sealed behind the tip.
Designed for direct mounting
through the wall of a tank.
The polysulphone tip is espe-
cially resistant to most acids
and bases.
Type Selection
Housing material
Tip material
Ordering no.
Ordering no.
Ordering no.
Ordering no.
NPN, Make &
NPN, Make &
PNP, Make &
PNP, Make &
break switching
break switching
break switching break switching
Cable
M12 Plug
Cable
M12 Plug
Stainless steel
Polysulphone
VPA1MNA
VPA1MNA-1
VPA1MPA
VPA1MPA-1
Stainless steel
Glass
VPA2MNA
VPA2MNA-1
VPA2MPA
VPA2MPA-1
Nickel plated brass
Polysulphone
VPB1MNA
VPB1MNA-1
VPB1MPA
VPB1MPA-1
Nickel plated brass
Glass
VPB2MNA
VPB2MNA-1
VPB2MPA
VPB2MPA-1
Specifications
Rated operational voltage
10 - 40 VDC
Ripple
10 V
Output current
Continuous
200 mA
No-load supply current
7 mA
Voltage drop
2.5 VDC
Protection
Reverse polarity,
short circuit, transients
Ambient light
50.000 lux
Transient voltage
1 kV
Delay after power-on
20 ms
Operating frequency
30 Hz
Indication for
Output ON
LED, yellow
No LED indication on plug types
Sensing accuracy
Liquid level difference
Horizontal mounting: 5 mm
LED indication on plug types
Vertical mounting: 2.5 mm
Pressure
10 bar at +60C (+ 140F)
Environment
Degree of protection
IP 67
Operating temperature
-20 to +80C (-4 to +176F)
Storage temperature
-40 to +100C (-40 to +212F)
Liquid temperature
+100C (+212F) for
60 s
Housing material
Stainless steel or
nickel plated brass
Cable
2 m, 4 x 0.3 mm
2
, grey, 5.2
oil resistant PVC
Resistance
100
, extension possible
Weight
90 g
Tightening torque
Stainless steel
30 Nm
Nickel plated brass
30 Nm
External thread
3/8" (ISO 228/1)
CE-marking
Yes
Types VP, Modulated, Metal Housing
Optical
Ordering Key
VPB1 M NA-1
Modulated light
Built-in amplifier
Output: NPN or PNP, 4-wire (NO & NC)
Housing: Stainless steel or nickel plated brass
Tip: Polysulphone or glass
High chemical resistance to most acids and bases
Liquid and electrical circuit completely isolated
Power supply: DC models 10 to 40 VDC
2
Specifications are subject to change without notice (25.06.99)
Mode of Operation
The probe contains IR trans-
mitter, receiver and amplifier
with open collector NPN or
PNP output. The light source
is a Ga-As diode emitting
modulated, infrared light in
short pulses.
This level probe is thus insen-
sitive to ambient light (up to
50,000 lux) and suitable even
for adhesive liquids.
The conical tip of the sensor
forms an angle of 90. This
angle acts as a prism, i.e. the
beam, emitted from the Ga-
As diode placed in one side of
the sensor head, is reflected
internally to the phototransis-
tor placed in the other side of
the sensor head (fig. 1), pro-
vided that the tip of the sensor
is situated in free air. If the
sensor tip is immersed in a
liquid, always having a refrac-
tive index different from air
(fig. 2), the beam will be
refracted into the liquid.
All types of sensors can ope-
rate in oil, waste water, aque-
ous solutions such as beer,
wine, alcohol etc. without any
kind of accessory.
Dimensions
Wiring Diagrams
VP, modulated
PNP
NPN
Receiver
4 BK
2 WH
3 BU
1 BN
4 BK
2 WH
3 BU
14.5
17
19
14.5
17
19
Plugs: Standard M 12, CONH1A-.. or CONH1O-.. series.
Accessories
VP..M.A
VP..M.A-1
Receiver
Transmitter
Transmitter
Internal
reflection
Air
Refraction
into liquid
Liquid
Fig. 1
Fig. 2
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