Technical Status and Development Direction of China's Remote Water Meter

Abstract : This paper introduces the application characteristics and development process of pulsed, direct-reading remote water meter from the perspective of technical principle and practical application, and expounds the market view of pulse-based, direct-reading type that will take two days into the world and take each share.

China's remote water meter is roughly divided into two types: pulsed and direct-reading. Because there is no ready-made technology to learn from, the two types of remote water meters have experienced numerous twists and turns in their respective development processes. In particular, the initial product of the pulse-type remote water meter has caused many difficulties and defects, and there have been many failed projects and defects. People even have doubts about the ultimate success of the pulsed remote water meter.

Since 2003, direct-reading remote water meters have been simmering in the market with their own theoretical superiority, and they have been forced to pulse-type, making the pulse-type remote water meters, which are not yet stable, even worse. In this regard, the author has conducted in-depth analysis and discussion of the two methods of remote transmission from the aspects of theory, experimentation, application, and market, and published the article “On the Vitality of Switching (Pulse) Remote Water Meters”, supporting the pulse. Remote water meter.

Three years have passed. As of the end of 2006, the fact that the "Suiwei" self-retaining switch (pulse) type remote water meter has accumulated 1 million units ("China Water Supply and Water Saving" 2007.5.1) was further proved. According to the author's article, "... the vitality of the switch (pulse) type remote water meter will be long-term and powerful."

During this period, the direct-reading remote water meter was not reconciled to the theoretical level, the failure of one generation and the other. Then, pulsed, direct-reading, how their development; who will be in the fierce competition in the market "laugh to the end"; whether they can take up the responsibility of the future of China's meter reading. Please see the following analysis.

I. Technical Status Quo and Application of Pulsed Remote Water Meters The birth of China's remote water meter was started approximately 20 years ago, and the “Water Meter Remote Flow Meter” (Patent No. 3) was developed in 1987. After that, photoelectric, Hall, and single dry reed tubes were successively produced and applied. Because there was no market for residential automatic meter reading, the application of these technologies was only a few and partial. After 1996, residential automatic meter reading began to have a certain market. These technologies began to be applied universally and gradually exposed the instable and inaccurate defects, and ultimately failed. The double reed switch technology was successfully developed in 1997 (Patent No. 7) and has been applied. Compared with other technologies in the past, double reed pipes have much better accuracy and reliability. The author initially (1998) applied it to the automatic metering system for IC card water meter (Tianjin County, Tianjin) and achieved success. So far, this technology has been widely used in IC card water meters. However, this product still has the disadvantages of instability, leakage count, non-magnetic immunity, and more than one computer interface.

The most ideal product for the pulsed remote water meter is the self-retaining switch technology developed in 1998 (Patent No. 6). Due to the use of dual-sensing heads and self-retaining switch technology, the accuracy of the switching signal is 100%. Because this technology adopts the structure method above the water meter glass, it successfully solves the problem of anti-magnetic interference. Later, this product was designed as a sensor patch, making it easy to install and combine ordinary water meters throughout the country and even the world. It became a kind of "one minute to turn your ordinary water meter into a remote water meter." "The universal product. From 1999 to 2006, this self-sustaining switch sensor product has been used for more than 1 million applications, including only 194,000 in Beijing. The six-year scale application has fully proved that the self-maintaining switch remote transmission technology has fully achieved the remote transmission technical requirements of the automatic meter reading system in terms of accuracy, reliability, and stability.

In some special occasions where water pressure is not stable, there are sometimes phenomena that the water meter reverses, which is one of the causes of errors. In 2005, a successful remote-sensing technology with self-retaining switch function (patent number) that can measure backflow has been successfully solved. This technology has completely solved the reading error caused by the reversal of the water meter and has been widely used.

So far, in China, the development of the pulsed remote water meter has been completed for 20 years. It has come to an end with accuracy, reliability, stability, and versatility, and the era of impulsive sensing technology has been over.

II. Technical status and application of direct-reading remote water meters The concept of direct-reading remote water meters came about around 2001. The first was the resistance contact type and the photoelectric type, but due to the high process requirements, the difficulty of production. Large, as of 2003, basically no successful products have entered large-scale applications. Since then, two new direct-reading remote water meters have been produced, namely direct-reading video and direct-reading counts.

Photoelectric direct-reading remote water meter is divided into photoelectric and reflective photoelectric two. The principle is to set a fixed photo-emission source on one side of each character wheel, and to provide a reflecting surface or a receiving point for the perforation on the corresponding character wheel, using multiple (five) receiving points or reflecting surfaces. Different position statuses are used to determine what number of positions the wordwheel has turned to in order to determine the corresponding data. Since each digit depends on the remote position of the character wheel, this requires that the sensing positions on each character wheel and character wheel be relatively accurate. In the initial stage, such products generally suffered zero-point errors. After several years of improvement, some manufacturers have overcome this shortcoming, but there are still high-precision manufacturing requirements, which are detrimental to large-scale production and promotion. . Moreover, such methods are currently suitable for dry water meters. Wet (liquid seal) water meters are still in their initial stages.

Contact type direct-reading water meter in the early stage of this type of products are mostly resistance or potentiometer type, the principle is: install miniature brush on the word wheel, install resistor or potentiometer piece in the corresponding position, through the measurement Different resistance values ​​are used to determine the numeric position of the character wheel. The starting point of this type of product developer is often to make a breakthrough in the application of the wet water meter, but none succeeds. Recently, there has been a direct-reading remote-reading water meter that is entering the test phase. Its core part borrows the sensing principle of the aircraft oil meter. Not only is the sensing part highly accurate, but the entire contact part is sealed in the oil body. If the requirements are strictly met with the conditions of the aircraft's oil meter, we believe that this technology will be successful and will surely achieve breakthroughs in the products of direct-reading wet-type remote water meters.

The principle of direct-reading remote-reading water meter is to install a camera in front of the display window of the water meter mechanical character wheel. The digital image will be sent out, and then the image font will be translated into digital for computer storage processing. This product was first developed by Beijing Beibao Electric Co., Ltd. in 2003. Due to the fact that image transmission and digital decoding are not mature, the product has not been popularized. The second-generation product was developed by Nanjing Nuanyuan Company in 2007. Since the successful resolution of technical problems such as image processing, image transmission, and decoding and transmission, this technology has made breakthrough progress. At present, the product has been put into small batch production. And put into trial on the spot in Beijing, whether the success still needs to test the application time and the quantity of application.

Counting direct reading type remote water meter Counting direct reading type Remote water meter is a chip that collects switch (pulse) signals on each water meter, and keeps its work through the battery. The count signal collected from the self-holding switch sensor is recorded and stored in the chip, and the data read from the chip is the dial synchronization data. This product uses self-retaining switch sensing technology, intelligent memory chip technology and standard communication technology that are already very mature at present. Its entire production process does not require strict and precise, any dry, wet, cold, heat, and size Water meters can be arbitrarily combined. It is the most complete, most applied and most simple method of direct reading type remote water meters. At present, this water meter has more than 4 years of application experience. The disadvantage is that it still uses batteries to maintain its work, and six to eight years later, the batteries need to be replaced periodically.

Third, the pulse, direct reading type remote water meter will be ups and downs?

Compared with the pulse-type remote water meter, all direct-reading remote water meters have two common advantages: 1. The data read on the watch is the data displayed on the dial, not the pulse. 2. The data is mechanically recorded on the character wheel, which usually requires no power supply, and only powers up at the instant of reading the data. Therefore, we are not afraid of power outages and are not afraid of disconnection. In theory, the data it reads out and the dial data are always the same. Therefore, since the concept of a direct-reading remote water meter has been generated, people have been chasing favors and attention.

The pulse-type remote water meter is at a disadvantage on these two points because the signal transmitted by the pulse-type remote water meter is a pulse. The computer accumulates each remote pulse into data. If the accumulated data is accurate, the data is equal to Dial data. However, during this accumulation process, the accumulation will be interrupted and cause data errors regardless of line interruption or backup battery power failure. After the restoration, the base number must be reset. From this perspective, direct reading is much better than pulsed. Therefore, from a theoretical and promotional perspective, direct reading is in a dominant position. There are also people in the industry or companies that compare the shortcomings of pulse-type with the advantages of direct reading. It seems that the direct-reading “Dongfeng” has overwhelmed the pulsed “West Wind”.

Five years later, although the controversy continues, the conclusion seems to have become clear. The pulsed remote water meter was not overwhelmed but instead came tenaciously. In fact, the pulse-type remote water meter has never stopped the correction of its own weaknesses and achieved ideal results in the key links. 1. Due to the self-sustaining characteristic of the self-holding switch, each signal is accurate and fixed, and there is almost no possibility of error. 2. The remote transmission mode of the self-maintaining switch adopts the form of a switch (not a pulse). After the characteristics of slow operation of the water meter plus digital filtering are adopted, the interference in the remote transmission process can be completely eliminated. 3, for fear of power failure, the fear of broken lines, most manufacturers have adopted a micro-power design, and standardized wiring and management. In most cases, as long as the acquisition is accurate, the underlying data will be synchronized for a lifetime after being calibrated. 4. The cost of pulse-type remote water meters is much lower than that of direct-reading meters, which is very favorable for customers in the current meter- reading industry who only buy products without buying services, and have no spare space and compete for price competition.

It is precisely because of the shortcomings of the pulsed remote water meter and its advantages that it made the seemingly unadvanced pulsed remote water meter not only not eliminated, but it has made breakthrough progress in popularization and application. In many places, the pulse-based remote water meter has re-established a “reliable” image and has gained the trust of users. The successful promotion in Beijing is an example.

Can pulse-type remote water meters overpower direct-reading remote water meters? Nor is it. The author does not deny the superiority of direct-reading remote water meters. And since 2002, the author has developed a direct-reading remote water meter (Patent No. 9, 200620130878.8)

There are also many applications for counting direct-reading remote water meters. The author only maintained the proper status of the pulse-type remote water meter in front of the strong propaganda of direct-reading remote water meters. Like pulse-type remote water meters, the current shortcomings of direct-reading remote water meters can someday be overcome, but their large-scale applications (especially wet ones) are at least two years away.

When the direct-reading remote water meter gradually overcomes the difficulty of the process and the high precision required to enter its mature stage, the pulsed remote water meter has long been used in product reliability, product process, and application of the product in the project. User awareness has entered a very mature period. With the development of the automatic meter reading market, pulsed, direct-reading remote water meters will turn from opposition to reunification and from exclusion to complementation. There will be more manufacturers in response to market demand. The left hand will provide the pulse type and the right hand will provide the direct reading type. The direct-reading remote water meter and the pulse-type remote water meter will each take a share and two points in the next long period of time and share a bright future for the automatic meter reading market.