137 Series Optical Thickness Gauge

Thickness measurement using the unique properties of light

The 137 Series Optical Thickness Gauge from Bristol Instruments uses the unique properties of light to accurately measure thickness of a variety of materials. To make a measurement, light is directed onto the material under test. Reflections from every surface and layer interface are collected and then analyzed by an optical interferometer. This very precise “optical ruler” measures the difference in length travelled by each reflection to determine total thickness and the thickness of each layer. 

Accurate, repeatable, and reliable thickness measurement

The 137 Optical Thickness Gauge uses Bristol’s proven optical interferometer-based technology that operates in hundreds of research laboratories and manufacturing facilities around the world. Thickness of transparent and semi-transparent materials can be measured to an accuracy of ± 1.0 μm, with a long-term repeatability of ± 0.05 μm. This performance is guaranteed over long periods of time by continuously referencing the measurement to a built-in intrinsic standard of length. In addition, a unique interferometer design results in unmatched thermal stability to ensure that the system’s accuracy and repeatability are maintained over the specified operational environmental conditions. In order to provide even greater confidence, every 137 Optical Thickness Gauge is rigorously tested and certified with standards that are traceable to NIST.


Straightforward operation and flexible integration for manufacturing environments

Operation of the 137 Optical Thickness Gauge is straightforward, making it easy to get reliable thickness measurements every time. Measurement data is calculated using an on-board digital signal processor, transferred to a PC or local area network via USB or Ethernet, and then displayed using a convenient graphical user interface. Automatic reporting can be done using LabVIEW, .NET, or custom programming thereby eliminating the need for a dedicated PC. In addition, an optional integrated optical switch allows for as many as eight test stations with a single instrument making manufacturing applications more cost effective.  

A lower-priced alternative for non-contact thickness measurement

  • Measures thickness from one side without damage or deformation
  • Up to 31 total layers can be measured simultaneously
  • Highest accuracy of ± 1.0 μm (± 0.04 mils) 
  • Exceptional long-term measurement repeatability of ± 0.05 μm (± 0.002 mils)
  • Continuous calibration with built-in intrinsic standard of length
  • Traceable to NIST standards
  • Broad measurement coverage range of 35 μm to 40 mm
  • Straightforward operation and versatile integration
  • Rugged design for manufacturing environments

Tech Notes