Test Probes

Test probes are a great addition to many devices in order to establish a connection for testing or measurement purposes. Whether you're using an oscilloscope or a multimeter, having the correct probe is important for accurate measuring and the safety of the test. Test probes can measure several elements, including voltage, current, resistance to temperature and signals. Probes can come in many forms, from standard needle probes to more modular probes where you can use alligator clips, all at varying cable lengths for the job it requires.

Types of Test Probes

There are many types of probes that can be used for various applications. These include:

Needle Point Probes

Featuring a needle point tip to allow for precise location for testing. Some needle-point test probes can pierce the surface of a cable for testing without causing damage. The needle tip is generally made from stainless steel for durability and lifespan. Connections can be made through banana connectors for a swift and secure connection.

Fused Probes

These probes provide an additional layer of protection for the individual when carrying out an electrical test. Fuse test leads feature a built-in fuse to protect against a short circuit, for example. Rather than shorting out or rupturing the internal components of your device, the test probes will protect you and your device from harm.

Spring Test Probes

Also known as a contact probe, these are great for testing semiconductors or PCBs with a reliable electrical contact for their functionality and impact of a component. Their make-up includes a spring-loaded contact plunger located inside a metal tube. They’re typically gold-plated because of gold's electrical conductivity properties.

Multimeter Needle Probe

A multimeter needle probe is a type of test lead specifically designed for use with multimeters. It features a long, fine, pointed metallic tip, similar to that of a sewing needle, allowing for precise contact with small test points, surface mount components, or closely spaced terminals on electronic circuits. This type of probe is particularly useful for troubleshooting and diagnostics in electronics, where access to test points may be restricted.

Safety Considerations for Test Probes

Prioritising safety when using test probes is paramount to prevent electrical shock and ensure accurate measurements. Understanding the safety ratings and features of your probes is crucial for working confidently in various electrical environments.

• CAT (Category) Ratings: CAT ratings define the environments for which a test probe is designed in terms of transient overvoltage capability. Using probes with an insufficient CAT rating for the measurement environment can lead to serious injury or equipment damage. CAT II is for measurements on circuits directly connected to the low-voltage installation; CAT III is for measurements in building installations; and CAT IV is for measurements at the source of the low-voltage installation. Always match your probes to the CAT rating of the measurement environment.
• Voltage and Current Ratings: Test probes have maximum voltage and current ratings that should never be exceeded. Operating probes beyond these limits can compromise their insulation and safety features, increasing the risk of electrical shock. Always ensure the probe’s voltage and current ratings are suitable for the circuit being tested.
• Insulation Requirements: Proper insulation is critical for preventing accidental contact with live conductors. Test probes used in higher voltage environments require robust insulation. Ensure your probes meet relevant Australian safety standards for insulation, providing adequate protection in the intended testing environment.
• Safety Features: These features are designed to enhance user safety. Finger guards prevent accidental contact with the probe tip, shrouded banana plugs minimise the risk of shock when connecting to instruments, and retractable tips prevent accidental shorts when the probe is not in direct contact with a test point. Utilising probes with these safety features adds an important layer of protection during testing.

Maintaining Your Test Probes

Proper maintenance of your test probes will ensure their accuracy, reliability, and longevity. Regular care can prevent damage and ensure they function correctly for years to come.

• Regular Cleaning and Lubrication: Clean probe tips and cables regularly with a soft, dry cloth to remove dust, dirt, and contaminants that can affect contact resistance. For probes with moving parts, such as spring-loaded tips, occasional lubrication with a specialised electronic lubricant can ensure smooth operation.
• Inspect for Wear and Tear: Before each use, carefully inspect probes and cables for any signs of wear, cracks, cuts, or damage to the insulation. Damaged probes should be replaced immediately to prevent electrical hazards and inaccurate readings.
• Proper Storage: Store test probes neatly and avoid kinking or bending the cables, as this can damage the internal conductors. Using a dedicated case or hanger can help protect probes from physical damage and keep them organised.
• Correct Usage to Prevent Damage: Use probes only for their intended purpose and avoid applying excessive force or bending the tips beyond their limits. Incorrect usage can lead to physical damage and compromise the probe’s accuracy and safety.
• Periodic Calibration and Adjustments: For specialised probes requiring calibration, follow the manufacturer's recommendations for periodic checks and adjustments to ensure the continued accuracy of measurements

Avoid Common Mistakes when Purchasing Test Probes

• Avoid Underspecified Probes: Never purchase probes with safety ratings below your testing environment requirements. A CAT II probes should never be used in a CAT III or IV environment.
• Don't Ignore Connector Compatibility: Ensure your probes have the correct connectors for your test equipment or include appropriate adapters.

Industrial Applications of Test Probes

Test probes are essential tools across a wide range of industrial applications, enabling the measurement and analysis of electrical parameters in various systems and equipment:

• Discrete Manufacturing: In automated assembly lines and electronics production, test probes are used for in-circuit testing of components and PCBs, ensuring proper functionality and quality control of manufactured goods.
• Process Manufacturing: Industries such as chemical processing and pharmaceuticals rely on test probes to monitor and troubleshoot complex control systems, ensuring the integrity of sensors, actuators, and other critical electrical components.
• Energy and Utilities: Power generation facilities and distribution networks utilise test probes for the maintenance and troubleshooting of high-voltage equipment, ensuring the reliable and safe operation of power systems.
• Transportation and Logistics: In the maintenance and repair of vehicles and transportation systems, test probes are used to diagnose electrical faults in wiring harnesses, sensors, and control units.
• Telecommunications: Test probes are crucial for the installation, maintenance, and troubleshooting of communication networks and equipment, ensuring signal integrity and the proper functioning of network infrastructure.

Your Trusted Test Probes Supplier & Manufacturer

RS offers a range of test probes from leading brands, including Fluke, HARWIN, Hirschmann, and our own brand, RS PRO. Our selection caters to diverse testing and measurement needs across various industries. In addition to standard test probes, we also offer specialised probes such as thermocouple probes for temperature measurements and RTD probes for precise temperature sensing. Our knowledgeable technical advisors are readily available to answer questions you may have.

Explore our extensive range of test probes online today. For detailed information regarding our delivery options, please refer to our comprehensive Delivery Policy.