Model 520 Series HAND-HELD Electrostatic Voltmeter The Model 520 Series includes the Model 520 and Model 523. The TREKModel 520 Hand-Held Electrostatic Voltmeter (ESVM) Seriesproducts provide accurate, noncontacting measurements of electrostatic surface voltage for ESD applications in either ionized or non-ionized environments. Industrial applications include measuring charge accumulation in the LCD manufacturing process or measuring static charge in semiconductor production. The Model 520 series ESVMs utilize a new measurement technique that overcomes the disadvantage of the typical hand-held fieldmeter by providing surface voltage measurements which are essentially independent of the sensor probe-to-measured surface spacing. Model：520-1 ESVM Over a spacing range of 5 mm to 25 mm, the 520 voltmeter provides better than a 5% voltage measurement accuracy, while the typical fieldmeter provides a voltage measurement error in excess of 50%. An optional voltage monitor output is available (Model：520-2). Model 523 ESVM Over a spacing range of 30 mm to 60 mm, the 523 voltmeter provides greater than a 5% voltage measurement accuracy, while the typical fieldmeter provides a voltage measurement error in excess of 50%. The 520 series provides a measurement system which complies with standardized calibration equipment traceable to the National Institute of Standards and Technology. The 520 series hand-held voltmeters employ a slender sensor probe design that provides flexibility to make measurements in many locations which are impossible to reach using the large, bulky sensing surfaces of the typical hand-held fieldmeter. The slender design also allows for higher spatial resolution capability by allowing the measurement of small surface areas. A "hold" pushbutton retains the displayed measured voltage value for recording purposes. Model：520 Measurement Range 0 to ±2 kV DC. Model 523 Measurement Range 0 to ±20 kV DC. Model：520 Accuracy ESVM Monitor (Model：520-2) Better than ±5% of full scale over the entire recommended probe-to-surface separation range of 5 mm to 25 mm. Model 523 Accuracy Better than ±5% of full scale over the entire recommended probe-to-surface separation range of 30 mm to 60 mm. Model：520 Probe-to-Surface Separation (recommended) 5 mm to 25 mm. Model 523 Probe-to-Surface Separation (recommended) 30 mm to 60 mm. Stability Drift with Time Less than 600 ppm/hour, noncumulative. Drift with Temperature Less than 600 ppm/°C.
