Go to the type of soil you will be using the soil moisture meter in then completely saturate a small area of soil. The soil should be saturated and all standing water should be removed. Remove black hole cover from back of soil moisture meter. After removing the soil moisture meter tip cover put the tip of the soil moisture meter in the saturated soil. Take a small flat head screwdriver and put it in the calibration pod where the black cover was removed. Turn the calibration pod to the right and the needle in the soil moisture meter should move, stop soil moisture meter at 10 which is 100% saturated. Put black hole cover on and you are calibrated for that type of soil. Once done calibrating soil wipe soil moisture meter tip off and replace tip cover.
You will need a AA battery. Remove the 4 screws on the yellow box. The box should then pull apart. The first time it could be tight when pulling apart. You can take a screw driver to help loosen the box. Inside you will find a AA battery, remove and replace the battery. After replacing the battery and before putting the box back together get a glass of tap water no bottle water or filtered water. Put the soil moisture meter in the glass of water and a screwdriver in the calibration pod in the back of the soil moisture meter. Turn the screwdriver right and the left the needle in the soil moisture meter should move to zero and to 10. If the soil moisture meter moves back and forth the battery is good and soil moisture meter is ready. Put back together. YOU MUST RE-CALIBRATE YOUR SOIL MOISTURE METER IN SOIL.