Level Sensors Optical Types VP, Modulated, Metal Housing * * * * * * * * Product Description Optical level probe with modulated infrared light for detection of liquids. Selfcontained unit has built-in amplifier. Separate transmitting and receiving elements 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 Ordering Key sealed behind the tip. Designed for direct mounting through the wall of a tank. The polysulphone tip is especially resistant to most acids and bases. VPB1 M NA-1 Type: Refraction principle Housing material Tip material Light source Output type Connection Type Selection Housing material Tip material Ordering no. NPN, Make & break switching Cable Ordering no. NPN, Make & break switching M12 Plug Ordering no. PNP, Make & break switching Cable Ordering no. PNP, Make & break switching M12 Plug Stainless steel Stainless steel Nickel plated brass Nickel plated brass Polysulphone Glass Polysulphone Glass VPA1MNA VPA2MNA VPB1MNA VPB2MNA VPA1MNA-1 VPA2MNA-1 VPB1MNA-1 VPB2MNA-1 VPA1MPA VPA2MPA VPB1MPA VPB2MPA VPA1MPA-1 VPA2MPA-1 VPB1MPA-1 VPB2MPA-1 Specifications Rated operational voltage Ripple Output current Continuous No-load supply current Voltage drop Protection Ambient light Transient voltage Delay after power-on Operating frequency Indication for Output ON Sensing accuracy Liquid level difference LED indication on plug types 10 - 40 VDC 10 V 200 mA 7 mA 2.5 VDC Reverse polarity, short circuit, transients 50.000 lux 1 kV 20 ms 30 Hz LED, yellow No LED indication on plug types Pressure Environment Degree of protection Operating temperature Storage temperature Liquid temperature Housing material Cable Resistance Weight Tightening torque Stainless steel Nickel plated brass External thread CE-marking 10 bar at +60C (+ 140F) IP 67 -20 to +80C (-4 to +176F) -40 to +100C (-40 to +212F) +100C (+212F) for 60 s Stainless steel or nickel plated brass 2 m, 4 x 0.3 mm2, grey, O 5.2 oil resistant PVC 100 , extension possible 90 g 30 Nm 30 Nm 3/8" (ISO 228/1) Yes Horizontal mounting: 5 mm Vertical mounting: 2.5 mm Specifications are subject to change without notice (25.06.99) 1 VP, modulated Mode of Operation The probe contains IR transmitter, 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 insensitive 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 GaAs diode placed in one side of the sensor head, is reflected internally to the phototransistor placed in the other side of the sensor head (fig. 1), provided that the tip of the sensor is situated in free air. If the sensor tip is immersed in a liquid, always having a refractive index different from air (fig. 2), the beam will be refracted into the liquid. Fig. 2 Transmitter Receiver Transmitter Refraction into liquid Internal reflection Liquid All types of sensors can operate in oil, waste water, aqueous solutions such as beer, wine, alcohol etc. without any kind of accessory. Dimensions Air Wiring Diagrams 19 o14.5 17 Fig. 1 Receiver 4 BK 2 WH 3 BU PNP VP..M.A 1 BN 19 o14.5 17 2 WH 4 BK 3 BU NPN VP..M.A-1 Accessories * Plugs: Standard M 12, CONH1A-.. or CONH1O-.. series. 2 Specifications are subject to change without notice (25.06.99)