Measurement sensitivity is a critical factor when considering probe performance. The more sensitive the measurement, the smaller the threshold between pass and fail, so it is important to match the correct probe to the application.
The tube material is an important feature when selecting the right test probe for your application. The following is a summary of the options, characteristics, and color code identification of QA probe tube materials:
The “N” tube is a nickel silver tube that has no cladding or plating and is suitable for most bare board test applications or where probe resistance below one ohm is acceptable.
The “G” tube is a nickel silver base with a layer of gold plating on the outside surface. The plating covers the inside of the probe tube and considerably improves performance compared to the “N” tube.
The “P” tube is deep-drawn from nickel silver alloy, has precious metal clad on the inside surface, and is used for in-circuit testing where low and consistent electrical resistance is necessary. The deep-draw process hardens the precious metal, improves wear characteristics, and provides a precious metal layer of extremely uniform thickness along the entire inside surface of the tube.
The proprietary, high conductivity alloy “H” tube is gold plated. These tubes are used in high current applications, very humid environments, or where extremely low electrical resistance is required.
The proprietary, high conductivity alloy “S” tube is silver plated. These tubes are used when a lower cost option is required for high current, low electrical resistance, or non-condensing applications.
