Pulsotronic offers solid cables or connectors for the connection of the sensors with external devices. As standard cables, we are using PVC insulated cables with different construction or PUR insulated cables. You can have an overview over all available cables under "cable types".
Capacitive sensors detect conductive and insulating materials in solid or fluid state. They are used for level measuring in tanks, for content control of filling and packaging lines, for detection, positioning, control and counting of objects (for example at sequencing controls, conveyor or rolling belts).
For products that need to have a CE certification, the manufacturer has to conduct a conformity assessment procedure according to the current EU regulations and to mark the product with the CE symbol. Relevant regulations for Pulsotronic devices are among others the following: EMV Directive 2004/108/EG, Low-Voltage Directive 2006/95/EG for AC and AC/DC sensors as well as different basic technical and product standards.
Extraneous light can disturb the effect of an optical system. In generel the receiver cannot distinguish if the light that it receives comes from the corresponding transmitter or any other source (for example from the sun). To minimise this impact, the transmitted light is pulsed with a certain frequency. The receiver only counts the part of the light that has the same frequency. The other light ("extraneous light") is suppressed in its effect. For applications where extraneous light is important, for example at very brightly illuminated working places or under direct sunlight, there should be imperatively used a kind of amplifier that can be used with clocked light. It can detect switching operations with frenquencies of up to 500 Hz. Faster operations that should be controlled have to use an amplifier with non-clocked light.
The sensor's connection cables should not lay in parallel in one cable duct with cables that conduct inductive loads (for example contactor coils, magnetic valves, motors etc.) or the currents of electric engine drives. The cable lengths should be as short as possible but can amount up to 300m if they are laying favourably (small coupling capacitance, small interference voltages). To decrease the interferences, the following actions are possible: - Distance to interfering cables > mm - Shielding - Activation of coils (contactors, magnetic valves, relays) with RC elements or varistors
see also: Rated Operating Current Ie
After the transmitted light leaves the sensor, it runs together and concentrates in the focus.
For inductive sensors, the correction value shows the reduction of the switching distance for materials that deviate from FE 360 (ST37).
Typical factors are:
Material | Correction value |
steel | 1 |
copper | 0,25 … 0,45 |
brass | 0,35 … 0,50 |
aluminum | 0,30 … 0,45 |
stainless steel | 0,6 … 1,0 |
nickel | 0,65 … 0,75 |
grey cast iron | 0,90 … 1,05 |
Specific scanning ranges for objects with different reflection characteristics are defined by the use of the correction factor.
Correction Value | Objects, Surface |
1 | paper white, dull 200g/m² |
1,2 … 1,6 | metal, bright |
1,2 … 1,8 | aluminumum, black anodized |
1 | Styrofoam, white |
0,6 | cotton, white |
0,5 | PVC, grey |
0,4 | wood, pure |
0,3 | carton, black, bright |
0,1 | carton, black, dull |
The switching distance of an optical sensor to the standard calibrating plate is adjusted in the coverage Sd.
Even in the load circuit of a switched-off sensor remains a current flow - the cut-off current Ir.