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Gage Comparator
Gage Comparator

Gage Comparator


Dimensional measurement gages are comparator gages generally rated as either short or long-range, the distinction being the operational range of measurement.  The technology typically used is a lead screw, glass/steel scale encoder, laser, LVDT or some combination thereof.

The classic short-range comparator is a dedicated LVDT-based machine with a very small operating range. If this comparator is well maintained and operated properly by a skilled operator in a temperature controlled environment, sub micro-inch accuracies can be obtained.  The primary drawback of the short-range comparator is that it’s very time consuming. However not all short-range comparators are dedicated or LVDT-based.  Some long-range comparators may be temporarily employed in this mode when necessary.

In today’s industrial environment time is money and, in most cases, short-range comparator's level of accuracy may not be warranted.  Although Pratt & Whitney manufactures a complete line of long-range comparator dimensional measuring machines for both outside and inside measurement, all of them can also be used in a short-range comparator mode. When used in this way, the system accuracy increases.

The Pratt & Whitney machines most often used in short-range comparator mode are the:

1. Labmaster Standard or Laseruler.  Comparator accuracy is 1.6 micro-inches (0.04 microns).
2. External Supermicrometer (Model B, C, PC).  Comparator accuracy is 10 micro-inches (0.25 microns).

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