1. indoor extension <br> <br> indoor extension intercom and video intercom there are two categories of products, basic functions as intercom, unlock. With the continuous enrichment of products, many products also have the functions of monitoring, security alarms and disarming, household access, information reception, remote telephone alarm, message retrieval, home appliance control and so on. The video intercom extension has two types of color LCD and black and white CRT monitors. Many technologies are now applied to indoor extensions, such as wireless reception technology, video character overlay technology, and so on. The wireless connection technology is used for the indoor unit to receive the signal of the alarm probe, and it is suitable for the difficult wiring. However, there are major loopholes in the wireless alarm mode, as the continuous transmission of the emission source of the frequency will cause the host to fail to receive the alarm signal sent by the control head. Video character overlay technology is used to receive short messages issued by the management center.
There are two types of indoor units in principle design. One is an indoor extension with a code. The splitter can be simpler, but the indoor extension costs a little higher; the other type of encoding is done by a doorway host or splitter, indoor Extensions are very simple. The LCD screen of the color indoor extension has not yet been domesticated and the cost is high. This is a bottleneck that restricts the application of the color visual building intercom system. The appearance of the intercom extension is similar to the bread telephone and tends to be diversified. Visual extensions tend to be ultra-thin handsfree wall mounts, but the most popular ones are wall-mounted black-and-white visual extensions. Indoor extensions occupy a relatively large cost in the building intercom system. From the development point of view, color extensions with security alarms and information releases are used in high-end real estate applications, while mid-range mobile phones are mostly black and white video intercom extensions. Speak extension.
2. door host <br> <br> At present, both the visible indoor dispute machine or intercom room extension, most users require the use of visual door host for users to choose. The host computer at the entrance is the key equipment of the building intercom system. Therefore, the appearance, function and stability are the main points of the manufacturers' competition. The main materials of the doorway are aluminum alloy extrusion profiles, die-casting or stainless steel shell stamping and forming. In terms of effect, aluminum alloy extrusion profiles have advantages. There are two kinds of liquid crystal display and digital control at the entrance of the host computer. The liquid crystal display cost is higher, but the display content is more abundant, especially the indispensable component of receiving the short message. In addition to the basic functions of calling the resident, the host computer at the door must also have the function of the call management center. The infrared auxiliary light source and the nighttime auxiliary keyboard backlight are the functions that the entrance host must have. The ID card technology and the reduction of the read head cost make the proximity card access control technology be applied to the host computer to implement the card unlocking function. In addition, for the convenience of use, many products also provide ringback tone prompts, key tone prompts, call prompts, and various voice prompts. Other functions make the performance of the door host gradually perfect.
3. Management Center
The management center machine generally has the basic functions of calling and alarm receiving, and is the basic equipment of the community networking system. The use of a computer as a management center greatly expands the function of the building intercom system. Many manufacturers spare no effort to make their integration in management software such as three-meter, patrol and other systems. With the system hardware, the management center connected by a computer can realize information release, community information inquiry, property service, call and alarm record query function, and setting up disarm record check function.
Our key products are litharge using in assaying of precious metal, and lead nitrate using in gold mining. Lead nitrate is used as medical astringent; tanning material for leather-making; dyeing mordant; photograph promoting agent; flotation for ore; chemical reagents; and also used for making fireworks, match, and other lead salts. In the mean time, we are sourcing the other chemical reagents for our mining customers in Australia, Canada, Africa etc.
1. Product name:lead nitrate
2. Character: white crystal powder, relative density 4.53(20), easily soluble in water, liquid ammonia, light dissolve in ethyl alcohol, not dissolve in concentrated nitrate acid, solubility 56.5g/100g water (20). Dry lead nitrate decompose at 205-223. Damp lead nitrate decompose at 100, first become Pb(NO3)2 . PbO, go on heating, then become PbO. It is strong oxidant, putting together with organics will lead it burning, noxious.
3. Application: Used as flotation reagent for gold ore and other ore.
Mining Chemicals,Mining Chemicals Cationic Pam Flocculant,Copper Mining Chemicals,Blufloc Pam Mining Chemical
Gemhold (SJZ) Trading Co., Ltd. , https://www.gemhold.cn