Heart rate measurement is performed by wearing a heart rate sensor around the chest. To eliminate measurement errors, it is recommended to moisten the electrode pads with water or apply electrolyte cream to the pads. If you have sensitive skin, moisten the electrode pads with water and wear it over a thin shirt. Chest hair may interfere with measurement in some cases. See illustrations 1. Attach the sensor to the HR strap. 2. Wear the HR strap by sliding the hook over the other end of the strap. Wind the HR strap around your body and adjust the length to suit your chest (underbust). Overtightening the strap may cause discomfort during measurement. Wear the heart rate sensor so that TOP faces up. Ensure that the electrode pads are in close contact with your body. If you have dry skin or are wearing the sensor over a shirt, measurement errors may result. In such cases, moisten the electrode pads with water.