Explanation on signal transmission
Explanation on water meter with signal transmission function.
Detailed explanation is listed on methods of signal transmission for long-distance water meter. Signal transmission can be separated into three categories, these are two-coiled transmission, three-coiled transmission and four-coiled transmission. For two-coiled transmission, the signal is transmitted by dry reed pipe. For three-coiled transmission, the signal is transmitted mainly by dry reed pipe, hall components or photoelectron. For four-coiled transmission, the signal is transmitted mainly by hall components and photoelectron. For three-coiled transmission, besides the above two sensors, a new type sensor with zero power consumption can also be used. The below is listed with methods of signal transmission by structure drawing in tree shape map. Detailed introduction for each method is also available.
1. Structure drawing on methods of signal transmission

2. Explanation on methods of two-coiled signal transmission
Signal is transmitted by dry reed pipe for the method of two-coiled transmission. Dry reed pipe can be one piece or two pieces, but usually one piece only. One piece can be used against theft or without anti-theft type, both two dry reed pipe can be used for signal transmission.。According to customer requirement, resistor may not be added between dry reed pipes. Resistor can also be installed in series or parallel connection. In this way, when dry reed pipe was in cut or closed status, users can judge the status of water meter according to the value change of resistance between the ends of two drawing lines. Below is the detailed explanation
1.signal transmission of single dry reed pipe.
a Single dry reed pipe for signal transmission
Only one dry reed pipe will be used for signal transmission without anti-theft function. Dry reed pipe will firstly be magnetized for self-holding and get over the influence from the impact of water hammer.
Sketch map as below


b. anti-theft type
According to electrical pressure, check the transmission status of each dry reed pipe to avoid water purging effectively. When resistance values between the ends of two drawing lines are zero, it can be judged that water stealing exists. Sketch map is as below



2． Double dry reed pipes for signal transmission.
Two dry reed pipes will be used for signal transmission in turn. Rotation of water meter can be identified with external-connected circuit according to the connection or disconnection of signal lines or the change of resistance values between the ends of two signal lines. When two dry reed pipes are closed or joined, it can be judged that water stealing exists. Sketch map is as below.


3. method of three-coiled transmission of signal
The method of three-coiled transmission can be divided into two kinds, one is transmission by dry reed pipe and the other is transmission by hall components. In actual application, it can be divided into transmission by single pole hall components, two poles hall components, dry reed pipe against theft and double dry reed pipes in turn。Resistor of many kinds can be installed in series or in parallel connection according to customer requirement.
a .double dry reed pipe for signal transmission
One reed pipe is used for transmission and the other is for signals against water stealing. Power consumption is low. Working current is only several micro ampere, but it's possible to create shaky signals. Sketch map is as below

b. double dry reed pipes for signal transmission at intervals
Signal is transmitted in turn at intervals by two dry reed pipes. When two dry reed pipes are closed at same time, it can be judged that water stealing exists. Power consumption is low. Working current is only several micro ampere. Problem of Shaky signal is solved. Sketch map is as below.


2. Signal transmission by hall components
a． Single pole hall components
This method of transmission is very accurate, working current is 5mA，working pressure is 3-15V。The defect is that when signal is transmitted, magnetic steel is just stopped at the boarding edge of signal transmission. When vibration is produced at pipeline where meter is installed, it is possible to create shaky signals. Sketch map is as below.

b. Two poles hall components（Locking type）
For two pole hall components, signal can only be transmitted after one induction of N pole and S pole between magnetic steel. Thus by this method the shaky condition can be avoided effectively. Working status is very stable. Working current is 5mA, and pressure is 3-15V. sketch map is as below

c. New type sensor
Dry reed pipe is widely used due to its low power consumption and aptness for reading copying system. The defect is the problem in reliability of mechanical touch point. By hall components, this problem is solved effectively, but as its power consumption is large and working current is over 3MA, it is difficult for the reading copying system. This type of sensor have combined the both advantages and improved the level of water meter sensor. Because of the different processing circuit in later grade, it can also be divided into two types, one is locking type ,the other is pulse type. Pulse type is with time-setting function besides the function of locking type. In this way, the width of pulse can be adjusted, this provided support for later processing for users. Meanwhile, the power consumption is much lower than locking type.
Technical data: working pressure:：3～12V working current：<1uA frequency for signal transmission：0～10KHZ。Sketch map is as below

4. Method of four-coiled transmission of signal
In four-coiled transmission, usually the signal is transmitted by double hall components and two photoelectrons. They also can be one hall component for transmission and the other one against theft. According to customer requirement, resistor of many kinds can be connected for support in processing in circuit in later grades.
Two hall components for signal transmission Sketch map is as below

2. The signal is transmitted by hall components and dry reed pipe against theft. In this method, hall components will be used for transmission of signal and dry reed pipe against theft. Sketch map is as below:

3.double transmission by photoelectron
In this method, the signal is transmitted by photoelectron with strong reliability, nice prevention from magnet disturbance and long life-span. Sketch map is as below.：

5. The above circuit diagram is only for reference.
They are designed for specific needs according to the principles of the sketch map。Meanwhile, it provided some support for processing in circuit in later grades. We are trying our best to offer you our sincere service.
The methods of signal transmission in water meter are continuously changing with the emerging of new type sensors.。However hall components and dry reed pipe, as the traditional sensors, are still standing in the leading position in the current phase.
Our company are trying our utmost to meet requirements from various customers, chasing tightly with the trend of the time based on the current position.。