Abstract :
The influence of the transistor on digital instruments is considered first and the example of its application to digital voltmeters shows how the product became practical in the late 1950s and then went through successive improvements in performance as the devices available improved. Later developments made the instrument more automatic and improved the cost and reliability. The influence of the transistor on analogue instruments did not start till much later but eventually the transistor displaced the valve and provided a much improved performance, illustrations from oscilloscope design show the influence of tunnel diodes on trigger circuits and how the alternate series/shunt feedback configuration is used in amplifiers to give very wide bandwidths. It is generally true that the introduction of semiconductors has resulted in cheaper instruments with better performance doing more complex tasks.
