Standard optical comparator charts

Dorsey Metrology uses satin ground glass of superior quality for all our optical comparator glass charts. The charts are very durable and will last for many years with proper care. Glass charts should be cleaned only with mild soap and water solution using soft cotton cloth. Window cleaners, thinners, and alcohol should never be used to clean your glass chart. All optical comparator glass charts are traceable to the N.I.S.T. and are available with certification at no extra cost.

Glass charts are typically required when:

  • The existing chart has been severely chipped or broken
  • The lines on the existing screen have faded or worn off

The new chart will remain in the comparator for an extended period of time.

Optical comparator overlay charts

Overlay charts are made of plastic and are placed over the existing glass screen. They are typically required when charts are interchanged on a frequent basis. Dorsey Metrology offers 4 types of plastic overlay material:

  • .007″ thick clear mylar
  • .007″ thick frosted mylar
  • .050″ thick clear vinyl
  • .050″ thick frosted vinyl

Optical comparator scales

Dorsey Metrology also offers three types of optical comparator scales:

  • inch/decimal
  • decimal/metric
  • multi-magnification

The inch/decimal and decimal/metric scales are available in glass and are useful for sight verification. The multi-magnification scales are useful for direct screen measurements of projected images on a comparator that is not equip with either digital readouts or micrometer readers. These scales are available in glass or 050″ thick vinyl. All optical comparator scales are traceable to the N.I.S.T. Certification sheets specifying traceability are available at no extra cost. Glass scales are available with serialized numbers. All scales are intended for sight verification and not for comparator calibration.

How to order your optical comparator chart?

When ordering your optical comparator chart, please have the following information available:

  • style of chart
  • type of optical comparator and model number
  • lens magnification
  • chart material
  • any additional information required for a particular chart or scale