Digital Micrometer for Scratch Depth, 8400K, by J Chadwick Co.

The 8400K Digital Optical Micrometer is a unique coating and surface inspection tool that offers speed, precision, and repeatability. Scratch depth measurement used to be an art. With the 8400K, you can now do it in less than 20 seconds. This time-saving tool was designed specifically for measuring the width of scratches and vertical depth of surface features. "Visual inspection" is standard for any component with scratch or corrosion pit damage, and maximum allowances are often specified. Other methods of visual inspection are time consuming and inconclusive.

The 8400K lets you measure the width of scratches using the reticle eyepiece and vertical depth of surface features, usually to evaluate the severity of mechanical damage such as scratches, corrosion, pits or blemishes difficult to observe by other methods. Accurate measurement is essential to determine whether a part should be kept in service, and the 8400K brings remarkable precision and integrity to this judgment process.

The 8400K is designed for use in the field. The sealed, non-magnetic case is dustproof and shock-resistant to withstand everyday shop use.

• Exact and repeatable. Very specific tolerances often apply to surface damage and exact measurements are essential todetermine if a part should remain in service. The 8400K allows “repair or replace” maintenance decisions to be made with absolute certainty, and backed up with precise measurement data.
   
• Eliminate Guesswork. Quickly and confidently perform visual inspections and make real assessments of damage severity.Avoid using substandard parts or scrapping parts that are still within safety and tolerance limits.
   
• Portable and Versatile. The kit has interchangeable bases and lenses for use on almost any surface, including transparencies and composites. Use one tool to inspect many types of damage; corrosion pitting, scribe lines, bubbles, crazing, and scratches on parts.
   
• Simple Operation. Unlike analog models, the 8400K is repeatable and requires no manual calculations. The digital LCD display is easy to read and toggles between inches and millimeters. Optional accessories allow data to be exported to a PC or handheld device.

• Measure scratches with accuracy and repeatability. Depth allowances are often specified, but proper measurement is needed to determine if a part should be kept in service. The 8400K performs this task quickly and easily, where other methods are time consuming and inconclusive.

  
      

• Measurement Technique: First, focus on a smooth surface next to a scratch. Then, zero out the digital display (you can choose a readout in either inches or millimeters). Next, focus on the bottom of the scratch. The digital display shows depth relative to the surface. "Floating Zero" means that no arithmetic is necessary to arrive at the result. If you can focus, you can perform cost-saving, accurate measurements of surface damage to mechanical parts.
      
• Applications:  Coated surfaces, windshields and other transparent materials may be measured for overall thickness, depth of crazing, and depth and width of imbedded bubbles or seeds as well as scratches. Shafts, couplings, airframes, masts, castings, windshields, fuselage skin (pitot tube area), leading edges, paint, turbine blades, fuel pump gears, props, rotor blades, sealing surfaces and much more.
    
• Options: The 8400K can output to a printer with Statistical Process Control (SPC), or be linked to a PC. These options provide hard copy for documentation, traceability, and trend monitoring.

The 8400K measures the distance between two points, or regions of interest (ROI). Clear, accurate results are produced in three easy steps:

• Step 1 is to focus on the first ROI, generally the good surface next to a scratch or pit.
• Step 2 is to set the display to zero with the touch of a button when the first ROI is in sharp focus.
• Step 3 is to focus on the second ROI, the bottom of the scratch or pit. When the second ROI is in sharp focus, the depth of the scratch (distance between the two points) is shown on the digital LCD display.
  
  Read and record the results - or export directly to a PC spreadsheet or hand held processor  (requires optional accessories). It’s that easy and takes less than a minute!