At present, there are two different types of optical fiber, which are single-mode optical fiber and multi-mode optical fiber (so-called "mode" refers to a beam of light entering the optical fiber at a certain angle). Multimode fibers are generally used for network connections in the same office building or in relatively close areas. While single-mode fiber delivers higher quality data and longer transmission distances, it is often used to connect office buildings or geographically dispersed networks. If optical fiber cables are used as the network transmission medium, devices such as optical transceivers must be added. Therefore, the cost is greater and it is less commonly used.
2. <br> <br> twisted-pair twisted-pair cable is a flexible communications, contains a pair of insulated copper wire, which is characterized by cheap, so widely used, such as our common telephone lines, etc. . According to the maximum transmission rate, twisted pair can be divided into 3 categories, 5 categories and 5 categories. The rate of Category 3 twisted pairs is 10 mb/s, Category 5 up to 100 mb/s, and Super Category 5 up to 155 mb/s or more, which is suitable for future multimedia data transmission requirements. Therefore, it is recommended to use 5 types or even 5 types of doubles. Stranded wire. Twisted pair can also be divided into shielded twisted pair (stp) and unshielded twisted pair (utp). Although the stp twisted pair has a low rate (only 4mb/s), it is much more resistant to interference than the utp twisted pair, so the price is much more expensive. Now these types of twisted pair are cheaper, a few dollars, expensive. More than ten dollars can buy one meter.
In contrast, utp twisted pair prices are generally around one meter one yuan, which is relatively low. In addition, the commonly used 10m and 100m unshielded twisted pair is popularly known as 10base-t and 100base-t, which are often seen in the market. The rj45 crystal head is also used for the twisted pair cable. It is used to make the joint between the twisted-pair cable and the NIC of the network card. The quality of the cable is directly related to the stability of the entire network and cannot be ignored.
3. The coaxial cable is coaxial <br> <br> many friends a familiar class of transmission medium, which is wrapped around the cable center conductor by a layer of copper of insulated wire, its most important feature is interference With good capabilities, stable data transmission, and low prices, it was once widely used, such as closed-circuit television lines. However, more coaxial cables were used in the past, mainly because the cost of the bus structure network composed of coaxial cables is low, but the damage of a single cable may cause the entire network to collapse, and the maintenance is also difficult. This is its biggest drawback.
Coaxial cables used in Ethernet applications are mainly classified into coarse coaxial cables (10base5) and fine coaxial cables (10base2). Rough coaxial cables are not used much now, and there are still some markets for fine coaxial cables. Fine coaxial cable market price of a few yuan a meter in general, is not too expensive. In addition, the coaxial cable is used to connect with the bnc head. The coaxial cable sold on the market is generally a finished product that has been connected with the bNC head.
Vacuum pump means water ring vacuum pump or liquid ring vacuum pump or water ring circulation pump or water aspirator
1) SHZ-D iii : 2 Tap, 180w water ring vacuum pump
2) SHZ-95B: 5 Taps,550w water ring vacuum pump
water ring vacuum pump is always used for rotary evaporators, glass reactors, nutsche filter, short path distillation and Wiped Film Molecular Distillation system
Lab water ring ring Vertical Circulating Water Vacuum Pump is a new type of vacuum pump designed
with circulating water as working fluid and negative pressure generated by jet principle. It is
not only a vacuum pumping device, but also provides the reaction device. Circulate cooling
water. The pump has the characteristics of no oil, no pollution, corrosion resistance, low noise,
convenient and flexible. It adopts anti-corrosion movement or stainless steel movement,
vertical motor and multi-purpose machine.
Vacuum Pump,Becker Pump,Experimental Vacuum Pump,Vacuum Pump With Compressor
Zhongyi Kori(Zhengzhou)Equipment Co.,Ltd , https://www.korireactor.com