Instruction Electrostatic field tester is a non - contact portable electrostatic field tester. Two LED lights are configured to ensure that the measured object remains 25mm away from the measured object. The shell is made of anti-static material and has a grounding buckle to ensure reliable measurement results. It is can be used easily to measure ion balance voltage (offset voltage) for many kinds of ionizers using a ion balance plate provided. Specifications: Static voltage measuring range: 0 ～ ± 1.49 kV (Low range),± 1.0 kV ～± 20.0 kV (Hi range) Ion balance voltage measuring range: 0 ～± 200V Measuring distance: 25mm ± 0.5mm (between charged object and field meter) Response time: less than one second LCD display renewal rate: 5 times/second Accuracy: ± 10% Ambient conditions: 10 ～ 40 ℃ and 0 ～ 60 %RH Display: Large LCD display (digital and bar graph) Bar graph: red LCD for positive polarity voltage blue LCD for negative polarity voltage Precision: ± 1.0 kV for low range:± 1.5 kV for high range, ± 15 V for ion balance Digital reading: □.□□ => 0.0～± 1.49 kV (Low range) □□.□ => ± 1.0 kV ～± 20.0 kV (Hi range) □□□ => 0～± 200 V (ion balance) Power: 9V battery Features 1.Battery four-gear performance display. 2. The bar chart shows the electric field and strength. 3. Automatic range digital display. 4. Multi-function alarm prompt. 5. Shut down after 5 minutes. 6. Ion balance measuring board is available. 7. With LED lighting, you can read data in the dark. 8. When the sensor fails, ERR prompts. 9. With polyethylene packing box, grounding port. Item included(027082): 1*Handy Digital Electrostatic Field meter