Trek Model 541A Non-Contacting Electrostatic Voltmeter for EQS/ESD The Trek Model 541A Electrostatic Voltmeter (pictured at left with the Model 541PR-S probe) provides accurate non-contacting measurements of the electrostatic surface voltage associated with EOS/ESD processes. The instrument is configured with a miniature electrostatic field chopper probe that can be remotely located and easily positioned within process equipment to provide highly accurate, non-contacting, DC-stable, spacing-independent voltage measurements in either ionized or non-ionized environments. A 20x4 alphanumeric LCD screen displays the present measured voltage, the positive peak voltage, the negative peak voltage and additional menu information. Key Specifications • Measurement Range Model 541A-1: ±1 kV DC or peakAC • Measurement Accuracy: Better than ±1% of full scale over a • Alphanumeric LCD Display: 20 x 4 characters Typical Applications Include • Semiconductor • LCD • Electronic assembly • ESD-sensitive processes Optional Walking Test Adapter kits for the Model 541A allow analysis of charge levels accumulated on the human body per compliance with ANSI/ESD STM97.2. and IEC Standard 61340-4-5. See page 2 for details. • Chopper probe is DC-stable with or without incident air ion flow • Drift-free measurements • LCD screen displays present voltage and holds the most positive and negative values • Visual and audible alarms activate when the preset voltage threshold levels are reached • Voltage output monitor for remote monitoring or control • USB and RS-232 serial ports • NIST-traceable Certificate of Calibration provided with each unit • compliant • Optional Walking Test Adapter kits available TREK, INC. • 190 Walnut Street • Lockport, NY 14094 • USA • 800-FOR TREK 716-438-7555 • 716-201-1804 (fax) • www.trekinc.com •

Performance Measurement Ranges Model 541A-1 Model 541A-2 Speed of Response (10% to 90%) 0 to ±1 kV DC or peak AC 0 to ±100 V DC or peak AC Less than 50 ms for a ±1 kV step (541A-1) Less than 50 ms for a ±100 V step (541A-2) Accuracy 1% of full scale Monitor Output Model 541A-1 Model 541A-2 Output Noise Output Impedance 1/100th of the measured voltage 1/10th of the measured voltage Less than 30 mV rms* 47 W Features (cont.) Alarms Activated if measured voltage exceeds preset threshold limits; positive/negative limits may be programmed separately Visual Front-panel LEDs illuminate when...