Article: Transpiration with Ohaus Scout Balance & EasySense 2

Every so often something comes along in practical science that makes you wonder why you have done a piece of practical in the way that you do!

We have been looking at mass loss with time from a bagged up plant, where you have the aerial parts out in the open and the pot and soil locked away inside a plastic bag.

In the past I have used an old top pan balance and tried to remember to come back every 10 minutes and record the mass, plotting a graph by hand to show a trend. It is tiresome and seems out of touch with a modern science practical.

Along comes a new addition to the EasySense software  the ability to link to the Bluetooth adaptor of the new Ohaus Scout range of balances. Set up is a breeze, connect the adaptor to the balance, turn on to activate the adaptor, link the balance to the software and place the bagged up plant onto the balance.

Select start on the software and leave alone, come back 20 minutes, 24 or 48 hours later and the data is ready for your inspection, plotted, tabled and ready to go!

It is so simple and the data is so compelling, you even see the rate of mass loss changing as the light intensity around the plant changes. Why would you use a top pan balance and pencil and paper.

Using a fan is not a good option, unless you can afford something like a Dyson, the air coming off the blades of a desk fan is very turbulent and acts erratically on the leaf area constantly changing the force acting on the leaf and therefore the measured mass, if you are to use a moving air mass find the mass before and after using the fan – when the air flow is static.

We have created a free to download student and teachers notes of this practical which can be found on the EasySense2 app page.