GenRad 1422 Series IET LABS

GenRad 1422 Series – IET Labs

Precision Air Capacitor Standards for Laboratory-Grade Capacitance Measurements

The GenRad 1422 Series by IET Labs offers high-precision, ultra-stable variable air capacitors used as primary capacitance standards in critical applications. Designed for laboratory and metrology environments, the 1422 Series is particularly effective in AC bridge measurements and other substitution techniques, providing continuously adjustable capacitance with excellent mechanical and thermal stability.

Available in multiple models, the 1422 Series includes both two-terminal and three-terminal configurations to accommodate a wide range of measurement systems and connection requirements. Each unit is crafted with precision-machined components and high-quality insulation materials to maintain long-term reliability and minimal capacitance drift.

These capacitors are essential tools in calibration laboratories, where accurate and traceable capacitance standards are needed. Their fine adjustment capability, robust mechanical structure, and stable electrical characteristics make them ideal for use in bridge circuits and with high-accuracy LCR meters.

Features

• Continuously adjustable air-gap capacitor standard

• Ultra-stable performance with high mechanical precision

• Available in both two-terminal and three-terminal models

• Capacitance range from 1 pF to 1150 pF depending on model

• Direct reading dials with dual-range options

• Low dielectric loss and high insulation resistance

• Precision worm drive mechanism for fine adjustments

• Aluminum structure to ensure low thermal expansion

• Silver-alloy brush and drum for low-noise rotor contact

• Optional precision calibration for increased accuracy

Applications

• AC bridge measurement systems

• Capacitance calibration in metrology labs

• Use with high-precision LCR meters like IET 1693 or AH2500A

• Capacitance substitution in electronic circuit evaluation

• Educational and research laboratories

Specifications

• Capacitance ranges:

  • 1422-D: Dual-range 115 pF / 1150 pF (two-terminal)

  • 1422-CD: Dual-range 1.1 pF / 11 pF (three-terminal)

• Accuracy:

  • As low as ±0.05%, depending on model and calibration method

• Stability:

  • Excellent long-term mechanical and thermal stability

• Temperature behavior:

  • Matching expansion coefficients between components

• Zero capacitance:

  • Typically <0.1 pF

• Construction materials:

  • Rotor/stator: Aluminum

  • Insulation: Cross-linked thermosetting polystyrene (stator)

  • Rotor insulation (where used): Steatite ceramic

• Terminations:

  • Binding posts (two-terminal)

  • GR-874 coaxial connectors (three-terminal)

• Mechanical design:

  • Precision worm gear with silver-alloy contact system

  • Preloaded ball bearings for accurate axial alignment

• Calibration:

  • Supplied with certificate and correction chart

  • Optional 100-point high-resolution calibration available

• Mounting:

  • Bench-top or rack-mountable

• Origin:

  • Made in the USA

The GenRad 1422 Series is the gold standard for laboratories requiring exceptional accuracy and dependable capacitance performance over time.