The VPG/SI On-Board Legacy

A Past with Purpose

We’re proud to be a part of the VPG legacy. This vision spans over six decades and reflects the extraordinary vision of VPG founder, Dr. Felix Zandman.

Dr. Zandman developed the first generation of Bulk Metal® foil resistors and later, foil strain gages. The VPG line of solutions and technology were born from his many innovations.

At SI On-Board, we continue Dr. Zandman’s vision with our own tradition of achieving the highest level of performance throughout all of our weighing solutions. With over 3 decades of experience, the extensive SI portfolio leads the industry in test and measurement across multiple markets.

Through VPG’s many strategic acquisitions, we’re able to offer the solutions you need to operate with confidence knowing you have the gold standard in precision measurement capabilities. In addition to SI On-Board, other VPG brands include the George Kelk Corporation, Stress-tek, Pacific Instruments, Dynamic Systems Inc. (Gleeble), and Diversified Technical Systems, Inc. Our dominance in global manufacturing, sales, and distribution networks (including facilities in Canada, China, France, Germany, India, Israel, Japan, Sweden, Taiwan, the United Kingdom and the United States) offers unprecedented reach and industry leadership.

SI On-Board technologies (including Stress-tek) serve over 70% of the total market with more than 17 On-board patents. In every scale, we utilize our experience and history to provide the largest production of foil strain gages in the world!

Dr. Zandman’s credits include:

Product Development

  • PhotoStress® – Photoelastic Coating Method of Stress Analysis
  • Foil Resistor Technology – Essentially Zero Temperature Coefficient of Resistance
  • Photoclusion® – Photoplastic Measurement of Bite Conditions (Bio-Mechanics)
  • Special Strain Gages
  • Thermal Shroud used on guns of Merkava Tanks (First-Hit Accuracy)


  • “Study of the Deformation and Rupture of Polymers”, F. Zandman (Scientific and Technical    Publication of the French Ministry of Air Force, Paris, 1954)
  • “Photoelastic Coatings” F. Zandman, J. Dally, S. Redner (Iowa University Press, 1977)
  • “Resistor Theory and Technology” F. Zandman, P.–R. Simon, J. Szwarc (Scitech, Inc., 2001)
  • “Never the Last Journey” F. Zandman, autobiography (Schocken Books, 1995)

*Additional published papers in the fields of Photoelasticity, Strain Gages, Moiré, Resistors, and Bio-Mechanics


U.S.A. and abroad – 71 patents in the fields of Photoelasticity, Strain Gages, Moiré, Resistors, Potentiometers, and Semiconductors

We rely on our SI On-Board Scales every trip to ensure that we maximize our loads.

Jake ThompsonTTT Timber, Inc.

We use SI On-Board Scales on our fleet of log trucks. Whether our trucks are running off road in harsh conditions or over the highway, the SI scales consistently provide accurate readings. We rely on our SI scales every trip to ensure that we maximize our loads. The majority of our haul routes pay by the ton so it is critical for us to maximize our revenue. Our SI On-Board Scales are very accurate, and our confidence in them has been proven through years of use. We have been pleased with how easy the scales are to use and adjust, and with their longevity in rugged conditions.