By Nick

The micro-balance and associated paraphernalia

Science is full of tedious little jobs that have to be done. Steps along the way, that involve sitting down and doing repetitive tasks again and again. Once I have successfully milled my stalagmites (see here) its on to the weighing room.

This is no ordinary balance no. It is a micro balance, and it is very sensitive, capable of weighing down to 0.0000001 grams. Putting something more than 5 grams on the balance and it doesn’t work!

In order to get a balance this sensitive to work properly, it needs a few additional features. For a start, the balance has its own little plastic box, with a revolving door, to keep any airflow out. Just breathing near the thing is enough to change the reading.

Since I’m working with such small amounts of powder, typically 0.000150g, I have to use a paintbrush to pick up tiny piles of powder and transfer them onto a small piece of aluminium foil, and transfer the foil to the balance. You can also weigh little sea creatures, such as foraminifera on the balance, but these are much harder as they have a tendency to jump and escape when touched by a paintbrush – despite having been supposedly dead for tens of thousands or even millions of years!

Also the work is done inside a small room to limit airflow. The balance just wouldn’t work in a draughty lab. There are upsides to this: the ability to play music quite loudly for one. And downsides: it gets rather warm, quite quickly. In fact, at my old place of work, the weighing room, was pretty much a cupboard. Even on the coldest days, you’d be sweating in just a t-shirt after an hour of weighing and beginning to suffocate with the lack of air.

One must suffer for one’s science.