Measurement system – snap gauges are available for either metric (mm size) or English/Imperial (fractional inch size) measurements. It is highly recommended that an appropriate authority such as a UKAS approved laboratory carries out a full calibration on plain limit gauges at least once a year. In between UKAS calibrations at a frequency based on usage, plain limit gauges should be calibrated in-house. A typical in-house calibration would include a written procedure and an associated calibration record sheet, which would contain as a minimum, the following listed information: Plain limit gap gauges Thin/narrow gap sensor—Thin or narrow gap sensors area used to measure very small widths within a product or between the faces of components. Thin or narrow gap examples include the joint spacing between two surfaces before welding, brazing, or adhesive bonding; turbine blade to outer casing gap measurement; rotor to stator gap measurement; slot die coater gaps; disc brake rotor to brake pad gap; workpiece to fixture gaps and spark plug gaps. Feeler gages, optical or imaging gap gages, capacitance gap sensors, eddy current gap sensors, and air or pneumatic gap sensors are technologies used to measure or detect fine gaps. Gap detector / gap detection sensor—Gap detectors and gap detection sensors indicate the presence of a gap, clearance, spacing, void, break, or tear within a part or between two surfaces or parts.They provide only the gap's occurrence,not a direct reading or measurement of the gap. Some gap sensors can be set to switch or trigger for gaps below a specific size.

A GO gauge represents the maximum material condition of the product and conversely, a “NOT GO” gauge represents the minimum material condition. 5. Pin Gauges Web/wide gap sensor—Wide gap sensors detect or measure large breaks, voids or gaps in web, sheet, or panel applications. Transmitted or reflected light is often used to detect large gaps in webs or spacing between panels.Go length and No-go length – are the lengths associated with the go and no-go sections of the gauge. For progressive or combined limit gauges, the no-go section is interior to the go section on the gauge. Snap gauges are usually go/no-go gauges. This means that a single gauge has the capability to assess both the upper tolerance limit on the dimensional parameter being measured as well as the lower tolerance limit. In the typical fixed snap gauge, the jaws of the unit have two different measurement widths. The go gauge is set to the high limit of the shaft or part dimension and the no-go dimension is set to the lower or minimum limit value. To use the gauge to evaluate a part, the user places the part into the frame of the tool and first assesses if the part will enter the go range section (which is the larger of the two sections. If the part passes into the go range, it means that the part’s dimension (such as its diameter) is within the upper limit of the part’s tolerance and is ready to be evaluated against the no-go section. For a part to be accepted, it must not pass through the opening in the gauge for the no-go section. If it will not pass through that section, then the part’s lower tolerance on its measured dimension has also been satisfied, and the part can be accepted.

Fixed feeler gauges—Fixed feeler gauge and fixed step gages are mechanical gaging components used to measure gap, clearance, or spacing size.

Summary

This article presented a summaryof snap gauges, including what they are, the types, sizes & specifications, and uses. For information on other topics, consult our additional guides or visit the Thomas Supplier Discovery Platform where you can locate potential sources of supply for over 70,000 different product and service categories, including over 40 suppliers of snap gauges as well as suppliers of thread plug & ring gauges. Sources:

A traceability statement in this section would be required for all items and their relevant certification utilised for the calibration of plain limit plug gauges. Capacitance—Capacitance gap gages measure by utilizing the change in capacitance that occurs when the spacing between two conductors changes. All feeler gauges are somewhat thin. This is because the point of them is to fit into and measure gaps that are far too narrow for most other common measuring tools, such as tape measures. Material choices for snap gauges are typically tool steel, with options for carbide on the measuring faces to provide for wear protection. Snap gauge specifications and sizes

What Happens If You Install Fittings Wrong?

The B2 Gap and Step Gauge is an ideal measuring tool for assemblies where panel flushness and gap specification is paramount. The instruments design allows the inspector to take measurements single handed, a feature particularly useful when measuring almost inaccessible features. A resolution of 0.01mm couples with an accuracy across the measuring range of 23mm meets the majority industries requirements. The question is, how harmful will it be in this case? Is this a mistake you could easily brush off, or is it one that could have debilitating consequences down the road? Gap sensor / gap switch—Gap sensors provide a dimensional measurement of gaps or clearances. Gap sensors do not typically have a visual display. Air, pneumatic, and electronic feeler gauges can be considered gap sensors or gap sensing instruments depending on their display capability. Gap switches, gap sensing switches, and gap sensor switches provide an output to trigger activate or deactivate factory machinery. They Improve Installation Quality: By using a gap gauge to get the measurements and fittings installed correctly, you can feel more confident that your work is safe, secure and stable. No matter how handy a tool is, nothing is infallible, and nothing can guarantee perfect results every single time without fail. While the use of a gap gauge certainly provides a far greater likelihood that your pipe fittings will connect tightly together and perform as intended, many factors are still outside of the gap gauge’s control. Human error could come into play, materials could fail, or the gap gauge itself could fail.Put simply, a gap gauge is an excellent tool that helps provide greater levels of accuracy at large. However, it is not a cure-all that guarantees perfection in every single case. What Are the Benefits and Disadvantages of Using a Gap Gauge?