After hearing about our new displays in the previous blogpost, we thought you might like to know a bit more about how we look after our collections.
We have a very varied range of collections from natural history to fine art, archaeology to costume and almost everything you can think of in between.
To make sure our objects can be enjoyed for as long as possible we have to keep a check on the environment we keep and display them in.
We were delighted to obtain a grant recently from Museum Development Yorkshire to purchase new WiFi digital monitoring equipment to help us do this exact task.
With these digital monitors we will be able to track the temperature of the air in the cases and in our stores so we know the temperature of the environment that the objects are in.
We can also measure the amount of moisture that the air can hold at that temperature. This is called relative humidity (RH).
The two measurements are linked, as warmer air can ‘hold’ more moisture than cooler air. We want both of these measurements to remain as stable as possible to prevent any damage to the objects.
We will be training our staff and volunteers in what changes to look out for using the new monitors.
How do we monitor the collections environment?
For mixed collections like ours we normally aim for around 18-20 ˚C and 50% RH. Some collection items need a lower RH level than this. We can use separate boxes, cupboards and display cases with absorbent silica gel to create ‘microclimates’ for these items, like Shakespeare’s First Folio, which has its own conditioned case.
If it gets too cold and damp, metal items like our lead mining tools would develop rust. Mould might grow on the leather items.
If it’s too warm and dry, wooden objects like the Robert ‘Mouseman’ Thompson furniture might shrink and crack.
High temperatures and damp air together can also encourage insect pests like carpet beetles, clothes moths and silverfish to breed. They can cause damage to lots of different types of objects, like silk and wool items and even the glues in things like books and furniture. We definitely want to avoid these pests.
So you can see why it’s important to get the display and store environments just right!
What does this enable us to do better?
Our new monitors will mean we can track our cases and storage areas in real time. Alarms and graphs will let us know if there’s a rise or fall in temperature and relative humidity outside the boundaries we set.
Having a good idea of the environmental conditions in the cases will also help us share fragile and special objects like the 2,000 year old Flasby Sword which has an iron blade inside a copper alloy scabbard. It is a very difficult object to get the environmental conditions right for as it needs a low RH to prevent the iron blade rusting further.
If we find out there’s an environmental problem in the cases or in the stores through our monitoring, we can often use simple solutions such as adjusting the heating or using moisture absorbing products like silica gel. That’s why it’s good to find out about an issue early on before it causes damage to an object.
Monitoring the environment might not be something you ever think about when you visit a museum, but behind the scenes work like this is vital to help our objects survive to be enjoyed into the future.
Thank you Museum Development Yorkshire!