2, try to take a little longer to reduce the measurement error, such as 1000 meters, the cable intermediate joint must use "F-type joint" and coaxial double-pass (cable equipment), do not use welding method, because the welding method destroys the cable Coaxiality and continuity of characteristic impedance.
3, measuring the DC resistance data of the cable: such as SYV75-5 cable 1000 meters, DC resistance core wire is 35-40 ohms, outer shield layer resistance 1000 meters is 24-36 ohms (the shielding layer is different, the resistance is very different) SYWV75-5 cable 1000 meters, DC resistance core wire is 18-22 ohms, outer shield layer resistance 1000 meters is 24-36 ohms; accumulation of this information is very useful, not only can judge the quality of cable materials, but also used for engineering Wiring and quality of the pipe are checked. If the person wears the pipe, the wire is broken, the resistance value becomes larger, the video signal becomes weaker, and the interference that should not occur also occurs. The probability of such an "accident" is very high, but Also often ignored.
4. Measurement cable high and low frequency attenuation characteristics: measure the head head and color sync head amplitude at the end, calculate the attenuation amount with 0.3V as 0db reference, the same head represents low frequency attenuation, and the color sync head represents 4.43M high frequency attenuation. , for example, the measured sync head of the 1000 meter line is 0.15V, and the db number of the attenuation multiple is calculated as “-6db/1000m†according to 20log, and the amplitude of the attenuation of the 4.43M color sync head after 1000 meters is 30mv, that is, 1 /10 times, the attenuation is -20db/1000m; with this method, the transmission quality of different cables can be accurately grasped, and the "frequency distortion (high and low frequency attenuation difference)" has an intuitive concept, you can accurately measure The difference between the SYV and SYWV cables of the same model and structure is good or bad. The difference and performance of different manufacturers are compared. It is also possible to compare the changes of different batches of products from the same manufacturer.
5, the above method can also detect the performance of the video transmission system and equipment: such as the transmission characteristics of each coaxial video cable in the project, the transmission characteristics of the optical transceiver (can be measured as good or bad, do not think so ideal), RF transmission, microwave Transmission characteristics, transmission characteristics of the twisted pair, distribution characteristics of the video distributor, switching characteristics of the matrix host, special attention should be paid to when the multi-output simultaneously switches the same input signal, if the number of switching paths is found to be greater, the attenuation is greater. It’s not right, it should be the same. After testing, you will master a lot of unqualified products.
6, observe the field signal, look at the field synchronization position distortion is not large (flat and uneven) - should be very flat; at the same time you can also use the oscilloscope to observe low-frequency interference: if the field signal has slow fluctuations, is 50/100 weeks interference There are a lot of "thatched" beatings, most of which are frequency conversion harmonic interference, disconnecting the far-end camera, short-circuiting the inner and outer conductors of the cable distal end, and directly observing the interference waveform and intensity at the end with an oscilloscope; this method can also check and test the anti-interference The true performance of the device.
Roll Forming Machine consists of feeding, molding and cutting board after color production appearance tidy and beautiful, high strength, durable, widely used in industrial and civil buildings, such as factories, warehouses, stadiums, exhibition halls, theaters room surface and wall.
Its components including roll forming parts,PLC, computer control system, hydraulic pump station system, automatic cutting system.
Roll Forming Machine must use high pulse input function, high input of excellent performance, choose AB phase interference ability. And by setting interrupt function, ensure accuracy.
Our company is the most powerful manufacturer in cold roll forming machinery in China.
Symple Specification need offered.
1 Coil Width:
2 Cover Width:
3 Rolling Speed:
4 Rolling Thickness:
5Machine Dimension(LXWXH):
There are some popular types of Roll Forming Machine:
1 Corrugated Roofing Roll Forming Machine
2 Glazed Tile Roll Forming Machine
3 Ridge Cap Roll Forming Machine
4 Roof And Wall Panel Roll Forming Machine
5 CZ Purlin Roll Forming Machine
6 Trapezoidal Sheet Roll Forming Machine
7 Light Steel Keel Roll Forming Machine
8 Floor Deck Roll Forming Machine
9 Sandwich Panel Roll Forming Machine
10 Double Deck Roll Forming Machine
Our product was passed strict quality inspection. We have testing department to make sure quality of machine are trustworthy. The quality of the Roll Forming Machine is very reliable.
If you have any questions, please contact with us directly, and welcome to visit our factory.
Roll Forming Machine
Roll Forming Machine,Cold Roll Forming Machine,Roll Forming Machine Design,Sheet Metal Roll Forming Machines
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