ONSETHOBO ZW Series Wireless Temperature and Humidity Recorder Wireless Monitoring of Temperature and Humidity at the National Archives in Washington

The importance of preserving historical data to provide accurate views cannot be overstated and provide insight into our present. Organizations such as the Washington State Archives now utilize wireless environmental monitoring to ensure good storage conditions for their records and digital archives.

The Washington State Archives is responsible for preserving millions of paper records, providing a vital account of the communications, decisions, and actions of the Governor, Legislature, courts, and state and local agencies in Washington State. Its documentation dates back to the founding of Washington DC in 1853. Meanwhile, the National Digital Archives facility was to be established in the United States today, the first to include more than 28 million searchable documents, photographs and other records online.

Hot spot monitoring

For the past seven years, the National Archives has housed a two-story building on Washington State University's East End. The facility systematically manages indoor air quality and power. Recently, the Washington State Archives has added Onset's HOBO® ZW Series Wireless Data Nodes ZW-001, ZW-003, ZW-005, ZW-006, ZW-007, ZW-008, ZW-RCVR, ZW-ROUTER for energy and environmental monitoring to ensure optimal performance of these systems.

"The importance of temperature and humidity monitoring in the preservation of our records cannot be overemphasized," explained Harold Stoll, network administrator at the National Archives in Washington. "For example, in the paper archives, we have a freezer to keep old negatives. They can be explosive if they get too warm, so the clock in the freezer needs to be monitored.

Stoll points out that temperature monitoring of the second floor of the data center is also important because a loss of cooling could cause the data system to crash, or worse, create a fire. Early detection and notification helps provide critical information crews need to take corrective action, as well as when a potential fire will raise the general fire alarm.

"To sum up, we have hot and cold water mixed in some hot channels," Stoll said. "We wanted to track fluctuations in temperature and humidity to get a better feel for how the air conditioning system was performing.

Wireless monitoring facilitates data collection

Initially, the National Archives in Washington looked at traditional stand-alone temperature and humidity loggers for environmental monitoring. However, when Stoll researched Onset's site, he argued that wireless data nodes offer significant benefits.

"Traditional data loggers would provide the data we needed, but we didn't want to spend a lot of time manually retrieving data throughout the building," Stoll recalls. "We think wireless networking can really help us a lot, and I'm really impressed that we can go with wireless technology for just a little more money."

The Washington State Archives has nine data nodes at the first level of document record keeping. Eight nodes are used to record temperature and relative humidity, while one ninth has a freezer with an external temperature sensor. Upstairs, where the data center is located, there are six data nodes recording temperature and relative humidity, including three external voltage sensors and four air velocity sensors.

Information from the data nodes is automatically sent to a receiver, which is then stored on the desktop computer. Accompanied by hoboware®Pro software running on the computer and providing real-time graphs of the individual measurement points Stall and his team