Stainless Steel Insulation Pump The pump body is provided with a hollow interlayer and inlet and outlet flanges, which can be used for heat transfer oil, steam, hot water and other media to heat and cool the liquid and the pump. Stainless Steel Insulation Pump,Insulation Pump,Ss Pump,Stainless Pump Jiangsu Qiantu Trading Co., Ltd. , https://www.qiantupump.com
The main overcurrent parts of this type of pump are equipped with hollow interlayers, and are equipped with functions such as steam, hot/hot water, heat transfer oil, etc. to heat the conveyed liquid and the pump, and to keep warm. When the conveying viscosity is large, it should be used. Reducer, speed regulating motor or pulley and other transmission methods to reduce the speed of the pump.
1, the classification of walkie-talkie
According to the type of communication terminal, the walkie-talkie can be divided into handheld radio, car radio (base station) and relay station (relay station).
2, frequency range.
Before picking up a walkie-talkie, it is first necessary to know whether the walkie-talkie has a network access license of the national radio management department. Second, we should understand the frequency of the intercom work, such as national regulations for the use of civilian radio frequency range of 400 ~ 420Mhz.
3, launch power.
Transmitting power is an important indicator of a walkie-talkie. It determines the talk distance, usage time, and whether it will cause interference to other communication devices. Therefore, when purchasing a walkie-talkie, you should know the transmit power of the walkie-talkie according to actual needs. The transmission power of ordinary civilian walkie-talkies is about 1W, and the transmission power of commercial walkie-talkies and professional walkie-talkies is about 4W. (The State prescribes that the transmission power of hand-held radios shall not exceed 5W).
4, call distance
Often when purchasing a walkie-talkie, it always involves the problem of distance. The actual call distance is related to the transmit power of the intercom and the environment of use or network conditions. General communication distance within 2-3 kilometers can be regarded as short-distance communication, for individual users, you can buy civil walkie-talkie. For a unit user, you can purchase a low-power walkie-talkie through application. If you want to ensure the communication effect, you can choose a professional regular walkie-talkie. Need to communicate within the city, communication distance within 3-10 kilometers, you can consider buying a professional walkie-talkie. If you are farther away, it is best to use a base station to communicate with a hand-held walkie-talkie, or a vehicle-mounted station and a vehicle-mounted station to communicate with a base station. We can use a car-mounted walkie-talkie with a relatively high output power. If the user needs more distances or better communication quality, he or she may consider using a cluster walkie-talkie without having a network. Cluster radio because radio network support, so the communication distance is relatively long, effective distance of 15-30KM This walkie-talkie needs network support, so once off the net, just like the mobile phone off the net, even if the two parties can not call face to face .
5, the type and capacity of the battery.
The type and capacity of the walkie-talkie have a direct impact on the use of the walkie-talkie and its use efficiency. Therefore, when purchasing a walkie-talkie, pay attention to the type and capacity of the battery. First, there are more nickel-metal hydride batteries and lithium-ion batteries on the walkie-talkie. Under the same volume, Ni-MH battery capacity is high, memory effect is small, the use of the environment: -30 °C - -60 °C, the price is moderate, high self-discharge rate, about 25%, and heavier weight. Lithium batteries have high energy density, large capacity and light weight under the same volume, and basically have no memory. The use of the environment: -10 °C - 60 °C, self-discharge rate of about 6%, the price more expensive than nickel-metal hydride batteries.
When purchasing a walkie-talkie, you should also pay attention to whether the battery is the original battery and how much the marked battery capacity is. If possible, you can use the equipment to perform a simple test on the battery and check whether the actual battery capacity matches the marked one.
6, warranty period and later maintenance
At present, there are many walkie-talkie brands on the market, which are full of exquisite features and the prices are different, and they vary greatly. However, before purchasing a walkie-talkie, it is still necessary to inquire the seller about the quality of the walkie-talkie and the post-maintenance. Otherwise, it will cause unnecessary trouble in the later period.