The Triplett Model SFM500 Electrostatic Field Meter is used for the non-contact measurement of an electrostatic charge on a body or object. It has a range of -19.000kV to +19.000kV and a measuring distance of 1" (2.54c). Measurements are read on the 4.5 digit (19,999 count) backlit LCD display. It features user programmable audible high/low alarm settings, Data hold function that freezes the reading on the display, Min/Max captures the highest and lowest readings, and a Zero function that clears residual readings on the display and resets it to zero. You can manually store/recall 99 readings.