Lake Sunapee in western New Hampshire is known for its exceptionally pure water quality. Much of the water flows out of cold underground springs rising from a bedrock aquifer. The lake has eight islands, several peninsulas and lake fingers, and seven beach areas, meaning there\u2019s room for many to cherish its beauty.<\/p>\n
In order to protect this esteemed natural resource, the member-supported, non-profit Lake Sunapee Protective Association carefully monitors the lake\u2019s water quality. The LSPA was founded in 1898 and is New Hampshire\u2019s oldest environmental association.<\/p>\n
The organization has been testing water quality in Lake Sunapee since 1950. A few years ago, a real-time water quality and weather data buoy was deployed in the lake to assist with monitoring efforts.<\/p>\n
Data is wirelessly transmitted from the buoy every ten minutes, and it is part of the Global Lake Ecological Observatory Network, or GLEON.<\/p>\n
Instruments on the buoy measure air temperature, wind speed and direction, humidity, photosynthetically active radiation, dissolved oxygen, and temperature.<\/p>\n
Temperature is measured every 2-3 meters down through the water column to provide a comprehensive lake temperature profile. The LSPA, however, recently needed to replace the buoy\u2019s temperature sensor string. Officials were impressed with the rugged hardware construction of NexSens T-Node water temperature sensors and chose them as the replacement.<\/p>\n
Each T-Node includes a completely sealed, extremely precise temperature measurement system with top and bottom waterproof connectors. The T-Nodes have a range of 0-50 \u00baC and an accuracy of +\/-0.1 \u00b0C for high-precision measurements. T-Nodes can withstand underwater deployments as deep as 100 meters.<\/p>\n
The T-Nodes connect with underwater cabling to build a string of measurement sensors that are suspended vertically in the water column. (T-Nodes can also be strung horizontally along the seabed.)<\/p>\n
The LSPA\u2019s data logging equipment needed an SDI-12 output interface to read the temperature profile data, so a NexSens SDL submersible data logger was utilized as an SDI-12 output controller.<\/p>\n
Unlike many data loggers, the NexSens SDL can also function in a slave mode, allowing it to output data in SDI-12 or Modbus format to third-party data loggers. With the SDL in place, temperature data from the T-Nodes can be read by the buoy\u2019s Campbell Scientific data logger and transmitted wirelessly along with other environmental data to a remote computer.<\/p>\n
Image Credit: <\/em>http:\/\/en.wikipedia.org\/wiki\/File:LSPA_GLEON.jpg<\/em><\/p>\n","protected":false},"excerpt":{"rendered":" Lake Sunapee in western New Hampshire is known for its exceptionally pure water quality. Much of the water flows out of cold underground springs rising from a bedrock aquifer. The lake has eight islands, several peninsulas and lake fingers, and seven beach areas, meaning there\u2019s room for many to cherish its beauty.<\/p>\n","protected":false},"author":3,"featured_media":21620,"comment_status":"open","ping_status":"open","sticky":false,"template":"","format":"standard","meta":{"footnotes":""},"categories":[3,7],"tags":[91,60,217,121],"class_list":["post-835","post","type-post","status-publish","format-standard","has-post-thumbnail","hentry","category-application_notes-htm","category-news","tag-buoy","tag-featured","tag-gleon","tag-temperature"],"remote_post_permalink":false,"remote_post_featured_image":false,"yoast_head":"\n