/ SUCCESS STORY

China's World-Famous Taizhou Bridge Uses HMT330 Humidity Transmitters to Extend Service Life

Taizhou Bridge, an important crossing on the Yangtze River in China, has been designed for a service life of 100 years. Almost three kilometers in length, the bridge is the world’s longest three- tower, two-main-span suspension bridge. The bridge’s lifelines – the non-replaceable main cables – are protected from erosion by a dehumidification system that relies on Vaisala’s tried and tested HMT330 series humidity and temperature sensors for reliable data gathering.

Jiangsu Province Communications Air pipe Planning and Design Institute Main cable Air inlet Limited Company provides Exhaust consulting services on a variety of construction projects. Their Filter Dehumidifier activities include planning, consultation, supervision, and project management for construction Blower projects such as roads, bridges, Cooler tunnels, railways, ports, navigation locks, as well as industrial and civil building projects. The company corresponding approaches. The one of the critical support elements is also involved in environmental, total cost of the project was RMB in this bridge type. Known as the landscape, and intelligent 9.37B (1B euro), with construction lifeline of the bridge, these cables are transportation system projects. In taking approximately five-and-a-half non-replaceable. Each consists of 169 2007 it was solely responsible for years. The design of the bridge takes strands, made up of 91 galvanized the design and construction of the account of the local environmental high-strength steel wires with a dehumidification system for the main conditions it is exposed to. Energy diameter of 5.2mm. The wires are cables of the Jiangsu Taizhou Yangtze efficiency was another important prone to erosion due to continuous River Bridge. consideration during the design exposure to harsh conditions such Taizhou Bridge, located between phase. as high winds and various other Taizhou, Zhenjiang, and Changzhou types of adverse weather. During in Jiangsu province, is an important Protecting the Bridge’s their service life, the main cables crossing on the Yangtze River and Lifelines are also exposed to vapors, rain, part of the province’s highway Designed for a service life of and etchant gas – all of which will, network. In total the road covers 100 years, the 2,490-meter suspension over time, reduce their strength. approximately 62 kilometers bridge consists of a main tower, Without sufficient protection, the including the river crossing, the anchors, saddles, main cable, slings, cables could eventually wear to a main body of the bridge and the and carrier bars. The main cables are point that threatens the safe use of

CEN-TIA-G-Taizhou-customer-story-B211390EN-B.indd 1 23.5.2014 10.46 the bridge. To address this issue, the bridge’s main-cable dehumidification Jiangsu Province Communications system because we pay attention Planning and Design Institute to accuracy and stability, says Zhu Limited Company decided to install a Dongqing, Project Manager from the dehumidification system for the main Jiangsu Province Communications cables. The system prevents erosion, Planning and Design Institute Limited thereby extending the service life Company. “Dehumidification is of the cables and the lifespan of critical to the maintenance of the the entire bridge. The installation cables, so Vaisala’s humidity and of dehumidification systems as a temperature sensors are critical solution to help protect cabling and part of the whole system. The risk extend operational life is a growing is massive additional costs in the trend for suspension bridges. form of manual troubleshooting and maintenance.” Thanks to the “We chose Vaisala HMT330 to Vaisala’s Proven HMT330, the bridge’s maintenance monitor temperature and humidity Technology Chosen for Its teams have real-time visibility of the Excellent Performance condition of critical areas and can conditions in the bridge’s main- conduct analysis based on historical cable dehumidification system In the tendering stage, several data to ensure science-based because we pay attention to suppliers were evaluated. In the end, decision-making in the maintenance Vaisala’s HMT330 series humidity accuracy and stability,” says of the bridge’s main cables. and temperature sensors proved to Zhu Dongqing, Project Manager be superior thanks to their excellent “The 48 HMT330 humidity and from the Jiangsu Province performance. “We chose Vaisala temperature sensors installed Communications Planning and HMT330 to monitor temperature function and monitor excellently” Design Institute Limited Company. and humidity conditions in the concludes Mr. Dongqing.

Challenge Solution Benefits ▪ Taizhou Bridge is the world’s ▪ 48 Vaisala HMT330 series humidity ▪ Bridge maintenance managers longest three-tower, two-main- and temperature transmitters were can easily make a real-time check span suspension bridge. installed to monitor the bridge’s of the humidity and temperature dehumidification system. conditions. They are also able to An accurate and stable humidity ▪ check alarms as well as access and temperature monitoring Temperature and humidity sensors ▪ historical data of up to four years. solution was required to monitor are used in exhaust and aspiration the dehumidification system of the vents, as well as the filter to ▪ The HMT330 transmitters bridge’s critical main cables. monitor the temperature and contribute to a faultless humidity of the air entering the dehumidification process, enabling As the cables are exposed to ▪ system. Temperature sensors are science-based decision-making ambient air and all kinds of adverse also installed in the coolers. in the maintenance of the main conditions for long periods of cables. This improves stability and time, reliable measurement was of Sensor data is collected in ▪ security, and contributes to longer critical importance. the master controller using a service life. distributed two-level monitoring The measuring equipment also ▪ mode. Manual troubleshooting and needed to be easy to operate and ▪ maintenance can be avoided, maintain. HMT330 sensors perform ▪ which helps to avoid massive accurately in harsh, corrosive additional costs. outdoor environments, and feature an IP65 corrosion-resistant shell. ▪ The HMT330 has a minimum battery lifespan of 5 years, ensuring no loss of data, even in the event of a network or power failure.

Ref. B211390EN-B ©Vaisala 2014 Please contact us at This material is subject to copyright protection, with all copyrights retained by Vaisala and its individual partners. All www.vaisala.com/requestinfo rights reserved. Any logos and/or product names are trademarks of Vaisala or its individual partners. The reproduction, transfer, or check out distribution or storage of information contained in this brochure in any form without the prior written consent of Vaisala is strictly www.vaisala.com/HMT330 Scan the code for prohibited. All specifications — technical included — are subject www.vaisala.com more information to change without notice.

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