Hold the unit far from metal and press the button briefly.The red LED lights up.Place the unit with the frint firmly and in a night angle against the surface you intend to measure.If the unit detects metal up to 1 mm under the surface,the green LED will turn on. If the coating on the metal is thicker,the yellow or the red LED light up.

• Press and hold the button to turn the unit off.
• If the unit is not used,it tums off after appriximately 45 seconds