III: How to operate 1. Loosen the cover board of the battery holder with a smal1 Screw driver, push the cover board backward to remove it, insta11 new 9V alkaline battery while mainly focusing on the battery polarity, push the cover board back on the battery holder and tighten these curing screw on the battery holder. 2. Hold the handle of the meta1 detector and change the three-position switch on the left from the off position to the alarm position. The green LED power indication light of the detector wi1l be turned on and one can hear a short beep. 3. Use a known meta1 coin to test your meta1 detector function. The buzzer sha11 give an alarm sound when the detecting set swings above the metal coin horizonta11y and passes the metal coin object. 4. Change the alarm position to vibration position, the palm sha1l sense the vibration and no alarm sound sha11 be heard when the detecting set swings above the meta1 coin horizontally and passes the metal coin object. Periodical test shal1 be performed before forma1 use to ensure normal operation. 5. Sensitivity adjusting methods: adjust the sensitivity in the “sensitivity adjusting hole” on the right of the meta1 detector with a sma11 s1otted screwdriver. Adjust c1ockwise to increase the sensitivity and anticlockwise to reduce the sensitivity. Steps are as fo11ows: firstly adjust c1ockwise ti11 you hear continuous alarm sound in non-meta1 testing (or non meta1 area).Then you can adjust anticlockwise a little, namely til1 the detector will not give an alarm sound. The metal object testing sensitivity of a one Yuan coin set by the factory is about 5 cm. Special tips: fake alarm will occur if you adjust the sensitivity too high to exceed your need. When you don’t need high sensitivity, you can adjust the detector antic1ockwise ti1l reaching the leve1 meeting your needs with a smal1 s1otted screwdriver. 6. Low voltage alarm: when you turn on the power switch of the metal detector (not test meta1 object) but hear continuous alarm sound given by the buzzer, it means the battery voltage has become low in the interna1 meta1 detector and you should replace it with a new one for later use. 7. Maintenance: please change the switch to the off position when you don’t use the meta1 detector and maintain its clean and dry appearance. To do that, you can use wet c1oth to wipe it but shall not use any chemica1 detergent. IV: Application 1. Entertainment Venues: Detect controlled knives on the premise of ruling out belt buckles, cell phone and keys. 2. Electronics factory: Prevent loss of finished products, semi-finished products and electronic components, has high detection precision and anti-interference ability. 3. Prison system: Prevent prisoners going into the cell with metal objects, has high detection precision and the accurate counting capability. 4. Court system/public security system: Detect controlled knives on the premise of ruling out belt buckles, cell phone and keys. 5. Hardware factory: Prevent loss of finished products, semi-finished products and precious metals, can detect metals on the premise of ruling out belt buckles, cell phone and keys.