I. Overview     JD-3001 Geiger counter is an intelligent instrument that can measure nuclear radiation and electromagnetic radiation. Within the measurement range, an alarm threshold can be set, and an audible alarm can be issued when the threshold is exceeded to prevent overdose and protect the safety of workers.   2. Important notice   1. Before use, please read the following detailed introduction carefully, and use the instrument correctly according to the manual.   2. It is forbidden to disassemble the instrument or throw it into fire.   3. Prevent the instrument from vibrating and dropping violently.   4. Do not let liquid flow into the instrument.   3. Product introduction   ① Digital temperature and humidity sensor.   ② LCD display.   ③ Mute button: Turn the alarm sound on or off. Default is to turn on sound.   ④ "+" button: Quickly switch between nuclear radiation detection and electromagnetic radiation detection. During menu setting, the cursor moves up and increases the value.   ⑤ Power button: Press and hold for 2 seconds to turn the power on or off.   ⑥ Temperature unit selection button: Convert between Celsius and Fahrenheit.   ⑦ "-" button: short press to start recording data, the screen will show " " symbol. During menu setting, the cursor moves down and decreases the value.   ⑧ Setting button: short press to enter the menu, long press for 2 seconds to exit the menu.     Fourth, the menu function introduction   1. Short press the "SET" key to enter the menu page, long press the "SET" key to exit the menu page.   2. Language setting: 4 operation pages are provided: Chinese, English, Japanese and Russian.   Move the cursor bar to the desired option and press the "SET" key to confirm.   Long press the "SET" key to return to the previous operation page.   3. Function switching: move the cursor bar to the desired option, and press the "SET" key to confirm.   Long press the "SET" key to return to the previous operation page.   Press the "+" button to quickly switch the main page.   4. Time setting: move the cursor bar to the desired option, short press the "SET" key, the background turns red, press the "+" key or "-" key to set.   Long press the "SET" key to return to the previous operation page.   5. View data: move the cursor bar to the desired option, short press the "SET" key to view the recorded data.   Long press the "SET" key to return to the previous operation page.   It can store up to 7 days of data, please connect the important data to the computer through the data cable to export.   6. Timed shutdown: move the cursor bar to the desired option, and press the "SET" key to confirm. The default is 5 minutes to shut down. The " " icon is displayed on the screen.   Long press the "SET" key to return to the previous operation page.   7. Alarm value setting: move the cursor bar to the desired option, short press the "SET" key, the background turns red, press the "+" key or "-" key to set. The figure on the left shows the default alarm thresholds.   Long press the "SET" key to return to the previous operation page.   8.