1. AC and DC supply, low power consumption, and ease outdoor or laboratory use; 2. Liquid crystal display and clear reading; 3. High-precision integrated circuit and specially made high-efficiency light source with the service life of up to 100,000 hours to effectively ensure the instrument can work stably for a long time; 4. Auto shut off function and low-voltage display function that remind the users to change battery, to ensure the accuracy of measurement results; 5. Equipped with measurement valve output inteace and able to be equipped with recording instrument;