A scientific instrument is an instrument used for scientific purposes. Most are measuring instruments. They may be specifically designed, constructed and refined for the purpose. Over time, instruments have become more accurate and precise.
Scientific instruments are part of laboratory equipment, but are considered more sophisticated and more specialized than other measuring instruments as scales, rulers, chronometers, thermometers or even waveform generators. They are increasingly based upon the integration of computers to improve and simplify control, enhance and extend instrumental functions, conditions, parameter adjustments and data sampling, collection, resolution, analysis (both during and post-process), storage and retrieval.
Individual instruments can be connected as a local area network (LAN) and can be further integrated as part of a laboratory information management system (LIMS). This can give Internet access to databases of physical properties, for example a peptide spectral library allowing results comparisons and advanced data analysis. Developers have used open source principles to rapidly improve low-cost open-source hardware for scientific measurements and to create open source labs. With the advent of low-cost 3-D printing scientists can manufacture many of their own components. The 3-D printers themselves can even be modified to function as research tools (e.g. fluid handling).
Some scientific instruments can be quite large in size, like particle colliders or radio-telescope antennas and antenna arrays that are miles or kilometers wide. The converse or nanoscale also has been applied, with much of the activity centered on nanomedicine, particularly as non-invasive medical imaging has exploded on the diagnostic arts and minimally invasive surgery and surgical robotics have come into use. Instruments on the scale of a single molecule may soon interact with our bodies at the cellular and biochemical level to collect diagnostic information and provide accurate drug delivery mechanisms.
Scientific instruments can be found on board sounding rockets, satellites or planetary rovers and controlled by radio telecommunication.