The sensors have to be in good contact with your skin to have qualified signals. If the biodata comes out after you press the sensor against your skin, it means there is a gap between the sensors and the skin.
Please adjust the headband a little bit.
Please find the rubber band that fits snugly as there are three sizes of rubber bands.
Please make sure there is no hair between the sensors and your skin.
When you speak or move your eyes, these facial muscle activities will interfere with signal detection. If the signal is not stable, try to relax your face and eyes.
Skincare products, cosmetics, and sebum will prevent the sensors from detecting signals. Please clean the skin with a wet wipe to improve signal quality if needed.
Dry skin or dryness caused by the environment will affect signal detection as well. Please moisturize the skin with a wet wipe to improve signal quality if needed.
After each adjustment, it takes 30 seconds to 1 minute to detect the signals. Just relax and take a few breaths.