Model 323 High-Sensitivity, DC Stable ESVM

The Trek Model 323 Electrostatic Voltmeter performs high voltage resolution, noncontacting, DC stable surface voltage measurements using a technique which maintains high measurement accuracy over a wide range of sensor probe to measured surface spacings.   This makes the Trek Model 323 ideal for semiconductor wafer surface voltage measurement as well as other critical applications such as surface work function measurements and disk drive assembly charge accumulation measurements.

Using a variety of user specified vacuum compatible sensor probe configurations, such as side view, end view, round or square body types, the Trek Model 323 features a 3½ digit LED display while providing analog outputs for external monitoring at various scale factors.   The analog outputs can be used to control an ionization system to enable measured surface discharging.

The Trek Model 323 employs the world renown Trek low impedance sensor probe design which assures better than 0.05% measurement accuracy in the range of 0 to ±100 volts over wide variations of temperature and humidity.  

The Model 323 is specifically designed for high sensitivity applications and has adjustments to compensate for many sensitive testing conditions. The response Speed control adjusts the speed/noise tradeoff of the AC response. The Drift/Spacing Null Adjustment minimizes the variation in zero offset voltage as the probe to test surface spacing changes.

The front panel has an easy to read 3½ digit LED display. The detected output voltage can be monitored through a 1:1 voltage monitor output and a switch selectable ratio of 10:1 or 20:1 voltage monitor output.  

The Model 323 is used for a variety of electrostatic applications including materials evaluation, electret studies, charge accumulation on disk drive assemblies, and other extremely sensitive ESD sensitive components.

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PERFORMANCE

• All specifications are with a Model 6000B-8 probe with a probe-to-surface separation of 1 mm.

  Measurement Range
  0 to ±100 V DC or peak AC.

  Sensitivity
  5 mV.

  Accuracy
  DC Accuracy
  Better than ±0.05% of full scale.
  Voltage Monitor Output
  Better than ±0.05% of full scale.
  Voltage Display
  Better than or equal  to ±0.05% of full scale ±2counts, referred to the voltage monitor.

  Speed of Response (10% to 90%)
  Less than 300 ms for a 100 V step (adjustable).

  Stability
  Drift with Time
  Less than 50 mV/hour, noncumulative.
  1:1 monitor output Drift with Temperature
  Less than 10 mV/°C.
  10:1 or 20:1 monitor output Drift with Temperature
  Less than 5 mV/°C..

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PRODUCT FEATURES

• Null Voltage Source
  A calibrated 10-turn dial representing a 10 volt supply, with switch selectable polarity, used to produce zero volts output when the probe is coupled to a known zero volt surface. Also used to null contact potentials on dissimilar surfaces.
  Range
  ±10 volts
  Accuracy
  1%
  Resolution
  20 mV.

  Response Speed Control
  A front panel potentiometer that adjusts the speed/noise tradeoff of the Model 323 AC response.

  Voltage Display
  3 1/2 digit LED display.
  Range
  Switch selectable for ±10 V or ±100 V full scale.
  Resolution 10 V Range
  0.01 V.
  Resolution 100 V Range
  0.1 V.
  Zero Offset
  ±2 counts, referred to the voltage monitor.
  Sampling Rate
  3 readings per second.

  Drift/Spacing Null Adjustment
  A back panel adjustment used to minimize the variation in monitored voltage values as the probe to test surface spacing changes.

  Voltage Monitor Output (1:1 ratio)
  A buffered 0 to ±100 V output providing a representation of the measured voltage.
  Scale 
  1:1 of the measured voltage.
  Output Noise
  Less than 20 mV rms (measured using the true rms feature of the Hewlett Packard Model 34401A digital multimeter).
  Output Current
  5 mA.
  Output Impedance
  100 ohms, nominal.

  Voltage Monitor Output (10:1 or 20:1 ratio)
  A buffered 0 to ±10 V output providing a representation of the measured voltage.
  Scale
  10:1 of the measured voltage or
  20:1 of the measured voltage (switch selectable).
  Output Current
  5 mA.
  Output Impedance
  0.1 ohm, nominal.

  Power Switch
  A two position switch.

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PROBE

Recommended Probe-to-Surface Separation
±1.5 mm, ±0.5 mm.

Standard Resolution Probes:

Model 6000B-7C 
End-viewing, round body.

Model 6000B-8
Side-viewing, round body.

Model 6000B-15C 
End-viewing, square body.

Model 6000B-16
Side-viewing, square body.

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ACCESSORIES

• Accessories Supplied
  • Operator’s manual and line cord.
• Optional
  • 344RA Full-Rack Mounting Kit (two instrument capacity)

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GENERAL

• Line Supply
  Factory set for one of two ranges: 90 to 127 V AC or 180 to 250 V AC, at 48 to 63 Hz (specify when ordering).

  Power Consumption
  12 VA, maximum.  

  Ground Receptacle
  Banana jack.

  AC Line Cord Receptacle
  Standard three-prong line cord receptacle with integral fuse holder.

  Operating Conditions
  Temperature
  5 °C to 40 °C.
  Relative Humidity
  To 85%, noncondensing.

  Dimensions
  108 mm H x 223 mm W x 380 mm D
  (4.25" H x 8.75" W x 15" D).

  Weight
  3.6 kg (8 lb).

  Voltage Monitor Connector
  BNC coaxial connector.

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CERTIFICATION

TREK, INC. certifies that each Model 323 is tested and calibrated to specifications using measurement equipment traceable to the National Institute of Standards and Technology or traceable to consensus standards. A Certificate of Calibration accompanies each instrument when it is shipped from the factory.
Low Voltage Safety Compliance
(EN 61010-1)
Overvoltage Category
CAT II: Local-level mains, appliances, portable equipment.
Pollution Category
Degree 1: Operate in environments where no pollution or only dry nonconductive pollution occurs.

Copyright © 2004 TREK, INC.  All specifications are subject to change.

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