The tricorder of 2266 was a compact instrument that featured scanning, recording, and computing technology.

The tricorder of the 2260s was a small, handheld device that incorporated a video screen in the upper left corner, and a speaker on the right. There was a series of control buttons, and it could also be activated by voice commands.

The tricorder was, in one compact unit, a portable sensor, computer, and recorder. It could detect abnormal phenomena in the immediate area, alert the user to an alien presence, and scan through solid materials to a depth of several thousand meters. The computer memory within the tricorder was equivalent to that of a super-computer of Earth's late-20th century, but it came packaged in an incredibly small microchip enclosed within the tricorder, and used an advanced form of mnemonic memory circuit which could process and store a virtually unlimited amount of data in nanoseconds.

Depending on the specific mission, the tricorder's memory could be enhanced with special scientific and historical programs to enable the crew to perform their tasks more effectively. The tricorder also worked like a miniature camcorder, recording visuals, sounds, and unusual phenomena; an entire planetside mission could be stored for future reference. This function was performed automatically and did not require the user to initiate the recording process. It was a 'smart' recorder, storing only key information so that the important findings of a ground mission could be reviewed in a few minutes without having to sift through hours of unstructured data. Upon the landing party's return to their starship following a mission, the recorded data from their tricorders was scanned by the ship's main computer and entered into the master databank. The tricorder became an essential part of Starfleet operations and landing party missions in particular, where it provided personnel with an easy way of scanning new environments, unknown materials, and new life forms. In many ways the tricorder was, and continues to be, the most important tool in Starfleet's ongoing mission of exploration.

In the 2270s Starfleet was rapidly upgrading all of its technology, including the tricorder.

The tricorder was redesigned in the 2270s as part of a shakeup in all aspects of Starfleet life. Its basic functions - sensing, computing, and recording - remained unchanged; the differences were more in form than in function. The case was changed from black to platinum, with a shell of plastic polymers to strenghten it. And the return of pockets to uniforms made carrying straps redundant; grip pads were added instead. Touch controls were minaturized and all inputs and interfaces were located on the top surface, which was angled to provide easy visibility when held. A simple numeric keypad dominated the interface, with a few adjoining panels and lights. There was one monitor screen, but visual output could be imaged on one of the multifunction panels. Sensors were located on the projected forward side. It featured only one module with movement - a swing-down panel, sometimes decorated with a Starfleet logo. The 2270s tricorder incorporated a thin data chip about 2.5 centimeters square and a drive slot for the chip was included along the control panel's rear edge, on the user's side. Storage for the chip was provided by a rack located on the panel's inside face.

The continuing evolution of handheld sensing and analysis equipment has lead to the deployment of Starfleet R&D's TR-590 tricorder X.

Starfleet's current tricorder device measures 15.81 by 7.62 by 2.84 centimeters and masses 298.3 grams. The casing is gamma-strengthened polyduranide. The control surfaces retain the familiar operation interface and 3.5 by 2.4 centimeter display screen. The major optronic subassemblies include the power loop, sensor assemblies, primary processors, control and display interface, subspace transceiver assembly, and memory storage units. Power is provided by an induction-rechargeable sarium-krellide energy cell rated for 36 hours of continuous use with all subsystems active. This value will increase with fewer active subsystems. The typical power level is 16.4 watts.

The available sensor assemblies have been increased to 315 mechanical, EM, and subspace devices mounted about the internal frame and embedded in the casing. 189 are clustered in the forward end for directional readings, with a field of view lower limit of 52.3 arc-seconds. The other 126 omnidirectional devices make measurements of the surrounding space. The previously available deployable hand sensor on the standard tricorder has been eliminated, made obsolete by the increased resolution of the main unit.

The TR-590 polled main computing segments (PMCS), the primary data processors, are divided among the five inner casing surfaces and are rated at 275 giga-floating point calculations per second. The data-storage sections include eight wafers of densified chromopolymer isolinear crystal for a total capacity of 9.12 kiloquads. The control and display interface routes commands from the panel buttons and display screen to the PMCS for execution of tricorder functions. The opaque control surfaces are fabricated from thin-film copper dilefinate infused with metallic dyes to fix the graphical content. The display screen incorporates a standard nanopixel matrix similar to that used in PADDs and consoles. Communications with other data units is provided by the STA, with range limited to 40,000 kilometers, similar to the communicator badge.

The difference between life and death for Starfleet personnel often rests on a small, simple-looking box called a medical tricorder.

The underlying design of the medical tricorder is a standard tricorder - a handheld, multi-functional device that integrates computers, scanning sensors, and data storage. Gathered information is analyzed by an internal computer which displays the results on a small screen built into the tricorder. The differences between a medical tricorder and the standard tricorder model lie in its dedicated life-sign sensors, medical analysis computer, and library modules.

It also has an optional medical peripheral (MP) device, measuring 8.5x3.0x3.0 centimeters, which is essentially a clip-on sensor and processing device. It is powered separately and has a total operation time of 18 hours. Housed inside the MP is a removable scanner that supplements the basic sensors by collecting and sending high-resolution readings to the tricorder's internal sensors detect objects directly in their path to produce information on the body's overall processes, including electromagnetic conditions, organ functions, and dangerous organisms. The tricorder can coordinate 86 electromagnetic devices, which are installed in its internal frame, exterior sides, and exterior top. Current medical tricorders are outfitted with 14 nickle carbonitrium crystal wafers, three isolinear optical chips, and an interchangeable library chip. In practical terms, this means a medical tricorder contains medical data for humans and most humanoid types, plus information on 217 DNA-based species of non-humanoids.