Climate Change: Monitoring the Museums Environment

data logger on display

data logger at work - Death Magic, Nicholson Museum

hidden from view

'Hidden' data logger- Death Magic, Nicholson Museum

Museums are worried about climate change - in this case, not in the way you might think…

The climate of collection stores and galleries are strictly controlled to ensure the long term preservation of all of the artworks, objects and specimens in our care. Specifically the temperature and humidity must remain stable to reduce the risk of serious damage by mold, insects and other pests. The wrong environment, such as too dry, too damp, too hot, too cold, can shorten the life span of an object, or increase its decay. Sudden changes of temperature can also cause physical damage by causing materials to split and separate.

Our main way of monitoring the environment is by placing data-loggers in all of our spaces. Many museums, including us, often place them in displays, ‘hidden’ from view.

How do data loggers work?

Each device, placed strategically in storerooms and galleries, record the temperature (in degrees centigrade) and relative humidity (RH level) over time. The device has a display window that alternates between displaying each of these levels. While all staff are able to view the immediate readings and can alert our conservation team to sudden changes, typically the data from each device is downloaded and analysed at regular intervals.

Graphs are the most common tool we use to understand how these key environmental factors change over time and to ensure that there is no substantial climate ‘creep’ outside of the acceptable ranges.

A new system
grapgh 1

Graph 1

We recently changed the system we use to monitor our environments.

Previously, each monitoring device needed to be brought back to the office to be plugged into a PC to have the data downloaded. This was incredibly time consuming. The new system allows us to take a USB thumb drive to device and download data in situ. This will, of course, save us a lot of time.

However, the main advantage of the new system is that it allows us to do sophisticated analysis of the data very easily.

One example is the ability to overlay graphs of the data from two data loggers so we can compare readings. This is especially useful where we need to compare data from a room with data from a cabinet inside that room. In graph 1 the blue lines represent data from a data logger in the Macleay gallery. The red lines represent a data logger inside a display case in the Macleay gallery. You will notice that the darker lines, which record the temperature, are essentially the same from both data loggers. However the lighter lines, which record the relative humidity, are markedly different. It tells us that there are some fluctuations in humidity in the gallery, but the humidity is more stable inside the display case.

Graph 2

Graph 2

Another example is the ability to visually show whether the environments are staying within the acceptable parameters. In graph 2 we can see very clearly in the left hand side that the temperature is between 18-22 degrees Celsius nearly 80% of the time. On the right hand side we can see that the relative humidity is within the range 40-70 100% of the time.

All of this information enables us to make informed decisions about how best to manage the collection to ensure that it will continue to be available for display and research for as long as possible.