The GenRad1621 Capacitance Measurement system is a completely self-contained system capable of capacitance measurements in increments as small as 0.1 aF (10^{-7 pF}) and conductance measurements in increments as small as 100 aU (10^-7 µU; equivalent to a shunt resistance of 10¹⁰ MΩ). Measurements are three terminal, with 2- or 3-terminal connection, and provision is also made for the connection of an external standard for comparison measurements.

Such capability and precision are usually accompanied by restricted frequency and complex operation. The 1621, however, avoids these difficulties. Little degradation of performance occurs from 10 Hz to 10 kHz and operation to 100 kHz is possible. Balances are achieved by in-line readout lever switches — easily adjusted and read correctly. All digits of capacitance and conductance, as well as pertinent multipliers, are also provided by BCD-coded contact closures, available-at rear-panel connectors for use by printers or data-processing equipment.

Three integrated units The 1621 Capacitance Measurement System is an assembly of three integrated instruments: A precision ratio-arm bridge, a highly stable oscillator, and an extremely sensitive detector. Most of the bridge's internal standards are enclosed in an insulated housing to reduce the effects of ambient temperature changes; unused standards are disconnected to reduce shunt capacitance at the detector input. The oscillator provides up to 125 V or 5 A for sufficient signal to be detected even with unbalances as small as one part in 10⁸ of 10 pF. The detector contains three meters to help you speed the balance: One displays the magnitude and the other two simultaneously display the in-phase and quadrature components of any unbalance.

Features:

• 3-terminai measurementswith 2- or 3-terminal connection
• comparison measurements
• simple lever balance with in-line readout