Q. Hi, I've had a go at making the moisture tester, first using copper track on a backing sheet and then using stripboard. I didn't have any of the 1k2 resistors, so ordered some from yourselves as spares, but the circuit seems to work fine without it. Any thoughts? This is rteally just to cover myself if any of the students figure this out!!!
A. Hi Mat, thank you for your question. You may find the probes are more sensitive to moisture making the indicator work before the soil is fully dry. The full data sheet can be found here.