From the experience gained by supplying systems to the immense Italian artistic heritage and from the technical collaborations with the most prestigious research institutes in the sector, LSI LASTEM is able to propose complete solutions for the monitoring of conservation, restoration, movement and fruition of the works art.
Museums, places of restoration and discovery, museum display cases, warehouses, archaeological sites and caves must be monitored for their preventive conservation. Every object undergoes changes due to the chemical-physical transformation mechanisms to which it is naturally subject. The dynamics of these phenomena, also called the deterioration process, depends in part on causes linked to conservation environments. If the aging of materials is a spontaneous process that cannot be stopped, we can instead try to slow it down by protecting objects and artefacts, building an environment more suitable for their conservation. Prevention therefore plays a fundamental role so that the objects can last as long as possible and transmitted in the best way to future generations.
LSI LASTEM offers a series of portable and fixed systems, single-point or multi-point systems, systems for indoor, outdoor or indoor / outdoor comets for environmental monitoring of works of art conservation.
The parameters under observation
The instrumentation measures the vast range required of thermo-hygrometric, radiometric and environmental parameters in general, which as a whole can determine the interaction between the environment and the building:
- Horizontal and vertical air temperature, surface temperature, radiant temperature
- Relative humidity
- UV-A radiation
- Air speed
- Air quality: O3 concentration, VOCs, H2S, NO2, CO2
- Meteorological parameters: temperature and humidity, solar radiation, wind, etc.
The objects in a museum can be made up of very different materials and with responses to the impact of very different environmental conditions.
Generally they are the microclimatic conditions (temperature, RH% and light) that favor or inhibit the establishment of chemical and biological degradation processes.
In museum practice, it is not correct to speak of temperatures that are too high or too low, but of incorrect temperatures depending on the type of artefact preserved. Improper values favor physical, chemical and biological reactions that do not help the correct conservation. Even profound and sudden variations in values can cause damage to artifacts.
- Influence on size and shape
- Influence on the speed of harmful chemical reactions
- Influence on the sources of biological deterioration (microorganisms)
- Acceleration of metal corrosion
- Color fading
- Increased fragility of materials
- Acceleration of chemical reactions
- Acceleration of physical processes
- Expansion of materials
- Dehydration of materials
The contact temperature is useful for assessing situations in which the works, for various reasons, may have surface temperatures different from the air temperature. The contact temperature is the actual temperature of the product, so its measurement is of great importance, if it were to be different from the air temperature. Furthermore, the temperature in contact as a function of UR% is the parameter to be taken into consideration for the possible formation of condensation and fungus.
The goal of each museum is to allow visitors to have a better view of the works. This can be in contrast with the need for some manufactured articles to receive little light that often due to old types of lamps or lighting from natural sources, contains part of ultraviolet and infrared radiation, can cause deterioration to the preserved works. The exposure or total dose (millions of light hours "Mlx hr") of light received is an important parameter for assessing exposure over time.
The photochemical reactions triggered by light containing above all UV cause:
- deterioration of organic material and changes in color of the artefacts.
- acceleration of oxidations
- acceleration of fragility
- discoloration, fading and alteration of colored pigments
- increased surface temperature of materials
Museums are often immersed in urban aerosol, often subject to low air quality that easily penetrates inside, has an effect on many exposed materials. The intensity and speed of the chemical attack on the surfaces affected by the presence of polluting substances is proportional to the values of Temperature and Humidity: the higher the Temperature and Humidity, the faster chemical reactions are triggered. In addition to the powders, inside the museums there are gases and vapors that have the ability to remain longer suspended. The most dangerous pollutants for works of art are:
- NO, NO2
The air speed, if not dangerous due to its mechanical effects of its action, is important to evaluate a good stirring of the air inside the showrooms. This shuffling becomes important in the event of a high turnout of public that produces high concentrations of CO2, or in the event of erroneous values of Temperature and UR% that can be mitigated with good air recycling.
Climate comfort for visitors and employees
The museum environment is visited by the public and experienced by the museum staff. Within these environments the best climatic comfort is sought, compatible with the needs of the people, but at the same time, optimal for the conservation of the works. The parameters we consider for the comfort evaluation are:
- Relative humidity
- Air speed
- Radiant temperature
The interaction between artefact and climate, in the meteorological sense of the term, is of fundamental importance in case of analysis in historical buildings, catacombs and caves. Where the internal and external measures as a whole can provide possible explanations for particular phenomena.
Monitoring of museum environments
Without the knowledge of the physical, chemical and biological processes that regulate the deterioration and aging of works of art, it is impossible to implement conservation practices. The procedures for carrying out the measurements inside the museum environments are described in the UNI10829 standard (Heritage of historical and artistic interest - Environmental conservation conditions). The systems can be more or less articulated according to the measurement needs:
Preliminary and routine findings
They serve to take cognizance of the situation. They are made to obtain initial values to be compared over time and possibly assess risk situations also in view of continuous monitoring. For this type of investigation, portable multi-measure systems can be used. A single device, mounted on a tripod, can be connected with different types of sensors. The system measures and stores the data in its memory to then be connected to the PC for data analysis. The duration of the measurements will depend on the variability of the microclimate in day / night cycles and possibly in the seasons.
They serve to monitor environmental variables for long periods. The proposed systems are usually multi-point and multi-measure systems, where a series of sensors are connected via radio or cable to a MASTER unit that stores all the measurements. They are usually non-fixed but transportable systems, as there may be needs for frequent movement of the sensors. The need may be that of monitoring or monitoring and control. The check can be performed at two levels.
1) Electrical outputs implemented according to programmable events and thresholds. They are made directly from the MASTER control unit or also, if present, from SLAVE control units
2) RS485 serial outputs with Modbus-RTU protocol from the MASTER control unit, the serial output corresponds to instantaneous values or average values on creeping statistical bases. In this case the measurements are sent to the building control system.
The instrumentation and measurement methods applicable to it comply with the UNI10829 standards (Heritage of historical and artistic interest - Environmental conservation conditions - Measurement and analysis).
LSI LASTEM produces instruments for monitoring museum environments. The systems have the following types:
- Instrumentation for portable monitoring
- Instrumentation for fixed and continuous indoor monitoring
- Portable and fixed meteorological instrumentation combined with instrumentation for indoor environments