Making a moisture sensor to check that a sports pitch is fit to play on In this engineering activity, designed for secondary school students, students will make and test a moisture sensor that referees can use to check the playability of a football pitch. This is one of a series of resources designed to allow learners to use the theme of the sport to develop their knowledge and skills in design and technology and engineering. This free resource focuses on making and testing a moisture sensor that referees can use to check the playability of the pitch. Activity introduction Your task is to make a waterlogging sensor that a referee can use to check whether the playing field is fit to play on. It should indicate when the pitch is too wet for play to safely take place. Follow the steps outlined in our free activity sheet to assemble your own moisture sensor circuit. Once the sensor is assembled place the moisture sensor in wet soil or grass to see if it works! After you have tested your moisture sensor circuit you can discuss with your teacher how successful the making of it has been. This activity will take approximately 50-80 minutes. What you will need A soldering iron, stand, sponge and mat/base Solder Moisture sensor circuit board A 9-volt battery and battery snap A 470-ohm, 1 kiloohm and 1.2 kiloohm resistor A transistor A 5 mm red LED A sticky pad The engineering context Sporting events require engineers of a wide range of disciplines to make sure that it runs smoothly and effectively. From structural engineers in charge of stadium design to textile engineers producing the players’ kits, the importance of engineers is huge. Electrical and electronic engineers need to have basic skills in circuit construction, including soldering components and testing electronic PCBs. Suggested learning outcomes By the end of this activity students will be able to make a moisture sensor circuit, they will be able to fit and solder components to a PCB and they will be able to test the moisture sensor circuit to check how well it works. Download the free activity sheet! All activity sheets and supporting resources are free to download, and all the documents are fully editable, so you can tailor them to your students’ and your schools’ needs. The activity sheet includes teacher notes, guidance, useful web links, and links (where appropriate) to the national curriculum in each of the four devolved UK nations; England, Northern Ireland, Scotland and Wales. Please share your classroom learning highlights with us @IETeducation.