Extensometry

In high temperature materials testing, it is standard procedure to transfer the mechanical movement of a test piece from inside the furnace to a cooler region outside before measurement is made.

However, during transfer, factors such as friction, thermal expansion and mechanical movements can lead to errors, so it is clearly preferable to convert mechanical displacement into electrical signals as close as possible to the test piece inside the furnace. Transmission of the signal across the boundary is thereby simplified, and greater accuracy can be achieved in testing. SJB has developed a range of instruments for high temperature materials testing that work on this principle.

Critical to success has been the development of a precision non-contact measuring system that can operate at temperatures up to 800C. Whether using creep, fatigue or compact tension instrumentation, the objective is to position a transducer, target and air gap as close as possible to the test piece inside the furnace. Mechanical movements are thus converted to electrical signals at the earliest possible opportunity.

SJB has also created high-performance instrumentation for a variety of special purpose applications.

Our UK clients include British Energy, GEC, Rolls Royce, Imperial College London and the National Physics Laboratory. International clients include NASA (USA) and Petten Establisment (Holland).