The S2001 is designed to locate and measure static charge potentials on product, people, equipment and packaging. The instrument uses a non-contacting, chopper stabilized field sensor and a ranging light mechanism to ensure correct measurements of electrostatic fields in all areas- even those using air ionization. The Fieldmeter is easily zeroed with the turn of a small knob and does not require re-zeroing between measurements. Powered by a 9 Volt battery, the S2001 features a conductive case and a convenient snap-on ground lead to facilitate grounding and increase accuracy. NIST Certified.