APPLICATION OF ISFETS IN CLOSED-LOOP SYSTEMS FOR HORTICULTURE

Since the seventies a shift has occurred in horticulture from growing in soil to growing on artificial substrates like rockwool.
This development opens the possibility of creating closed-loop systems where waste of raw materials can be reduced and the environment is not overloaded.
In this case precise know-how of water composition is necessary.

The basic principles of a measuring system, which can measure continuously the concentration of nutrients in water, will be presented.
The system is based on ion-selective field effect transistors (ISFETs) which have several advantages over other systems.
By appropriate calibration, high accuracy can be achieved over long periods of time.
Results for pH and potassium measurements in nutrient solution will be shown.
An accuracy of better than 10% (concentrations in mMol/1) was achieved.

I International Workshop on Sensors in Horticulture

H.H. van den Vlekkert, J.P.M. Kouwenhoven, A.A.M. van Wingerden

CHEMFETs, ionophores, sensor packaging

https://doi.org/10.17660/ActaHortic.1992.304.35