What’s an instrument?

What’s an instrument?

There was a time when an EE could answer that question with, “A piece of electronic hardware designed to measure a specific parameter or set of parameters.” Times seemed simpler back then, and so did the answers to questions.

Today the answer is wrong on two counts. For one, instruments are no longer simply “pieces of hardware.” Much of an instruments control and operation depends on the software that is designed into it.

And the software is what makes the second part of the answer wrong; an instrument is no longer “designed to measure a specific parameter or set of parameters.” What an instrument measures is determined by software.

Software’s role in instrumentation does not mean that hardware is unimportant. Were it not for the incredible capabilities of high-speed A/D converters and DSPs, modern instrumentation could not exist. What’s changed, however, is that hardware alone is no longer responsible for an instrument’s behavior.

And, as Martha Stewart might say, “That’s a good thing.” Not only are the capabilities of instrumentation greater than ever before, but acquiring the capability is less costly and time consuming.

For instance, there are instruments on the market today where upgrading performance is simply a matter of obtaining a software “key” from the manufacture for a set fee. Typing the key into the instrument unlocks software that lets the instrument perform new kinds of measurements.

Another case is that of card-based virtual instruments, where systems can be quickly and economically reconfigured with additional cards and new software, so as to repurpose the system for a new set of measurement tasks.

Essentially, software has taken over the role of control and analysis in today’s instrumentation. And it has added several new tricks to the test repertoire.

For one, test software can now reside in ICs and be accessed to verify the IC’s performance in situ . For another, it can manage a company’s test instrument resources to optimize their use. And software is becoming the way that standards specify how equipment should be tested to validate performance and ensure interoperability.

There’s still one area in which software hasn’t come to dominate measurement. It is still, for the most part, the engineer’s job to determine how best to make a measurement and what equipment to use. But with the application of AI techniques, software is likely to one day a least act as an engineer’s assistant in performing that test too.

Richard Comerford