Decade Boxes

Decade boxes are versatile test instruments that utilise a series of resistors, capacitors, or inductors to replicate a wide range of electrical values. Additionally, these decade box instruments can be quickly and easily substituted into a circuit, replacing standard value components. Their ability to be configured to virtually any resistance, capacitance, or inductance makes the decade box a convenient tool for various applications, including electrical testing, prototyping, calibration, and laboratory simulation.

Decade boxes are ideal for verifying the accuracy of test equipment and for troubleshooting across industries such as electronics, automotive, R&D, and education. And at RS Australia, you’ll find them in options that are ideal for both field and bench testing in local engineering environments.

How Does a Decade Box Work?

Decade boxes are non-powered devices, meaning they do not require an external power supply. These passive devices facilitate substitution within a test circuit and consist of switches and a series of resistors, capacitors, or inductors of different values arranged to form "decades".

What is a Decade?

Decades are set up in factors of ten. For example, a resistance decade box may have a 5-ohm, 2-ohm, and two 1-ohm resistors in the first decade. The second decade may have a 50-ohm, a 20-ohm, and two 10-ohm resistors, while the third decade might contain a 500-ohm, 200-ohm, and two 100-ohm resistors.

How Values are Selected

This arrangement allows for manual tuning to select desired values. In the example above, this three-decade box can be switched to any value from 1 ohm to 999 ohms in 1-ohm steps. Some decade boxes may have six or more decades to achieve very wide ranges and highly precise values.

Example Use Case: Calibrating a Multimeter

Decade boxes are characterised by their range, maximum resolution, and accuracy. Using a decade box for testing consists of setting the box to the desired value and hooking up the input device, such as a transmitter, controller, multimeter, etc. The digital display value of the input device should match the set value of the decade box.

Types of Decade Boxes

At RS Australia, you’ll find resistance, capacitance, and inductance decade boxes:

Resistance Decade Boxes

Resistance decade boxes are used to simulate resistors in circuit testing. These instruments offer a range typically spanning from a few ohms to hundreds of kilo-ohms. Also, resistance decade boxes are commonly used in calibration procedures and fault diagnosis to precisely introduce known resistance values into a circuit.

Capacitance Decade Boxes

Capacitance decade boxes allow for the simulation of capacitive loads, and they are valuable for testing timing circuits or filters, enabling engineers to evaluate circuit behaviour under varying capacitance conditions.

Inductance Decade Boxes

Inductance decade boxes are less common than resistance or capacitance decade boxes. They are used to simulate the behaviour of coils and are particularly useful in radio frequency (RF) applications and tuning circuits.

Essentially, these tools allow engineers to isolate and control individual electrical properties within a circuit—resistance decade boxes precisely mimic resistors, capacitance decade boxes emulate capacitors, and inductance decade boxes simulate inductors.

Industrial Applications of Decade Boxes

Decade boxes are valuable tools across various industries, providing precise and adjustable electrical values for testing, calibration, and design purposes.

Field Testing & Maintenance

Technicians use decade boxes for on-site calibration and testing of equipment. These tools allow for quick substitution of resistance, capacitance, or inductance, enabling efficient troubleshooting and verification of proper operation in industrial settings.

Educational Labs & Training

Decade boxes are essential in educational laboratories, where students and instructors use them to demonstrate and study the behaviour of passive components in circuits. They also provide a hands-on method for understanding electrical principles.

Product Design & Engineering R&D

Designers and engineers utilise decade boxes during the prototyping phase of circuit development. These boxes allow for quick adjustments to component values, facilitating efficient optimisation of circuit performance before selecting fixed-value components.

Calibration Labs & QA

Calibration laboratories and quality assurance departments employ decade boxes in test benches for precise equipment validation. These instruments ensure the accuracy and reliability of test and measurement devices.

How to Choose the Right Decade Box

When selecting the appropriate decade box, you need to consider the specific application and the electrical properties being simulated:

• Type of Simulation Required (Resistance / Capacitance / Inductance): Determine whether you need a resistance, capacitance, or inductance decade box, as each type is designed to simulate a specific electrical property.
• Value Range: Consider the range of values you'll need to simulate. For example, some applications may require a resistance decade box with a range of 0–1000 Ω, while others may need a range of 0–1 MΩ.
• Resolution and Steps: Evaluate the required precision of adjustment. Resolution refers to the smallest increment by which the value can be changed (e.g., 1 Ω steps, 0.1 Ω steps).
• Accuracy/Tolerance: Assess the acceptable level of deviation between the set value and the actual value. Higher accuracy decade boxes provide more precise simulations.
• Build Quality & Portability: Consider the durability and construction of the decade box, as well as its portability if it needs to be used in different locations.
• Voltage/Power Ratings: Ensure that the decade box can handle the voltage and power levels of the circuit being tested to prevent damage to the instrument.
• Number of Decades: The number of decades determines the range and resolution of the decade box. More decades allow for finer adjustments and a wider range of values. For example, a 6-decade box offers more precision than a 3-decade box.

Decade Box Manufacturer, Supplier & Distributor in Australia

RS Australia is a leading supplier and distributor of decade boxes, supporting engineers and technicians across the country. We offer a comprehensive selection of decade box options, including resistance, capacitance, and inductance decade box instruments. Because we always strive for customer satisfaction, we only carry products from industry-leading brands such as Cropico, Martindale, and Time Electronics, as well as our own high-quality RS PRO range.

What’s more, we are committed to providing reasonably priced electrical components and equipment. Whether you buy an ohmmeter, LCR meter, or decade box, you can ensure that you’re getting the best value for your money at RS Australia.

Buy Decade Box Kits Online from RS Australia

Order your decade box from RS Australia today and experience our simple and convenient ordering process. If you want the easiest way to place your order, browse through our online selection of resistance, capacitance, and inductance decade box options, complete your purchase, and have the products delivered to your location.

We also offer fast delivery services, and for more comprehensive details about the options and associated fees, please visit our Delivery page.