Sound, Light, Temperature & Humidity Level Monitoring
Measurement and control of temperature and humidity in the agricultural production process is widely used in food storage and greenhouse for plant cultivation where temperature and humidity need to be monitored. In these particular environments, temperature and humidity values tend to remain within a certain range. Therefore, beyond the scope of the field you need to adjust the temperature and humidity. Conventional monitoring systems require personnel at the scene to collect data to determine whether the temperature and humidity is within a limited range, resulting in waste of manpower and time, and inconvenience.
Control of temperature and relative humidity is critical in the preservation of library and archival collections because unacceptable levels of these contribute significantly to the breakdown of materials. Heat accelerates deterioration: the rate of most chemical reactions, including deterioration, is approximately doubled with each increase in temperature of 18°F (10°C). High relative humidity provides the moisture necessary to promote harmful chemical reactions in materials and, in combination with high temperature, encourages mold growth and insect activity. Extremely low relative humidity, which can occur in winter in centrally heated buildings, may lead to desiccation and embrittlement of some materials.
Every building and environmental control system will have certain limitations and it is important to recognize these limits when making climate-control decisions. Climate control ranges from completely uncontrolled to sophisticated systems that can provide accurate control for heating, cooling, and humidification or dehumidification. Knowing what systems exist and what impact existing systems or new systems may have on the building envelope is important. Un-insulated, historic buildings can be damaged simply by the installation of a central heating or humidification system. Such buildings may need major alterations to be compatible with the needs of their contents. In these cases, it may even be necessary to relocate collections to provide conditions suitable for preservation.
How to Improve the Climate
Once collection needs, current climate conditions, and system capabilities have been determined, measures to improve environmental conditions for museum, library, and archival collections might include:
Removal of collections from attics, which tend to be hot, or basements, which can be damp;
Ensuring windows and doors are well sealed against the outdoors with caulk, window coverings, weatherstripping, etc.;
Creation of storage spaces segregated by type of material (determined by material environmental needs);
Improvements in insulation and building seals;
Use of portable air conditioners, humidifiers, and/or dehumidifiers. It is critical to remember that temperature and RH are intimately related and the correction of one factor may alter the balance of other important factors (e.g., a dehumidifier may generate enough heat to require additional cooling);
Installation of central environmental controls.
Air Quality
Pollutants contribute heavily to the deterioration of library and archival materials. The two major types of pollutants are gases and particulates. Gaseous contaminants — especially sulfur dioxide, nitrogen oxides, peroxides, and ozone — catalyze harmful chemical reactions that lead to the formation of acid in materials. This is a serious problem for paper and leather, which are particularly vulnerable to damage caused by acid. Paper becomes discolored and brittle, and leather becomes weak and powdery. Particulates — especially soot — abrade, soil, and disfigure materials.
Controlling air quality is difficult and complex and depends upon several inter-related factors. Various standards for air quality have been suggested. However, until more experience is gained, the most reasonable recommendation is that the amount of pollutants in the air be reduced as much as practicable.
