Determine the total surface area of the leaves in cm 2 and record the value. Stepâ 2 Calculate the rate of transpiration/surface area. If you are using a gas pressure sensor to collect data, you can express these rate values as kPa/min/cm 2, where kPa (kilopascal) is a unit of pressure.Record the rate.etermine the total surface area of the leaves in cm 2 and record the value. Stepâ 2 Calculate the rate of transpiration/surface area. If you are using a gas pressure sensor to collect data, you can express these rate values as kPa/min/cm 2, where kPa (kilopascal) is a unit of pressure.
That's why cellphones are much more sophisticatedâand work in a completely different way. A cellphone handset contains a radio transmitter, for sending radio signals onward from the phone, and a radio receiver, for receiving incoming signals from other phones.
It sometimes seems as if our phones function like an extra limb on our bodies. Now, research demonstrates exactly how attached to the devices we really are. The typical cellphone user touches his or her phone 2,617 time every day, according to a study by research firm Dscout. But that's just the average user: T he study found that extreme cellphone users â meaning the top 10% â touch their phones more than 5,400 times daily.