CAPACITANCE DECADE BOXES

A capacitance decade box is a test instrument that replicates capacitance values; these values can be substituted into a circuit to replace any standard component value. They are a handy device for trying capacitor values in-circuit before selecting the optimal value to use in the circuit.

They can also be used to test multimeters and other capacitance measuring instruments.

They are for use in the field, the lab or the factory, and are popular in educational applications. 

The three main things to look for when selecting a capacitance decade box are:

  • the capacitance range
  • the accuracy with which the device replicates the value
  • the degree of resolution to which you can set the value

Aside from these three common features, capacitance decade boxes are available in a variety of shapes and sizes with different features (e.g. high stability types, different test frequencies, programmable types, rack panel mounting) from the following manufacturers.

IET LABS, INC

IET LABS

Check out the full range from IET LABS here

TIME ELECTRONICS

TIME ELECTRONICS

Check out the 1070 and 1071 Series here

ELC

ELC

Check out the DC05 Series here

EXTECH

EXTECH

Check out the 380405 Series

MARTINDALE

MARTINDALE

Check out the TEK905 Series here

They are available from online distributors such as Farnell and RS Components. These devices aren’t cheap; if your budget is limited, capacitance decade boxes are also available on eBay.