The rate and extent to which chemical reactions occur

7. Silicon Diode

The silicon diode sensor is a device that has been developed specifically for the cryogenic temperature range. Essentially, they are linear devices where the conductivity of the diode increases linearly in the low cryogenic regions.
Whatever sensor you select, it will not likely be operating by itself. Since most sensor choices overlap in temperature range and accuracy, selection of the sensor will depend on how it will be integrated into a system.

Different types of thermometers

The development of the thermometer was a gradual process spread over centuries, with many scientists playing around with different scales and sizes. The invention has become crucial to many industries, none more so than the healthcare industry.
Body temperature is one of the four key vital signs of the human body, and measuring it has been key to the evolution of healthcare practices, with the thermometer being an integral tool in saving many lives. If your body’s temperature (taken orally) is outside the normal range of 36.3o to 37.3o then it is likely there is something wrong with your health.
The increasing importance of the thermometer in the diagnosis of patients has led to many new types of thermometer being invented to aid with the ease of taking temperatures. This is achieved by creating thermometers which concentrate on different parts of the body, with some more effective than others.
Digital thermometers
The digital thermometer is a widely used item of temperature-measuring equipment that significantly overhauls and updates the traditional liquid-based thermometers of yesteryear.
The classic liquid mercury thermometer was first popularised through 17th- and 18th-century developments in the field of clinical science, and remained fundamentally unchanged as our go-to temperature-reading device right up until the invention of commercially viable thermistors in the 1930s. By that point, the core elements of basic thermography had already been broadly understood for many hundreds of years - arguably thousands, if we include the early observations of Ancient Greek scholars with their crude tubes of water and air.
However, modern digital thermometers and probes work on different (albeit related) thermographic principles. They deliver a number of key advantages over the old liquid-in-glass versions, making digital thermometers infinitely better suited to all manner of uses across a broad range of 21st century industries and applications.
How a digital thermometer works There are various different kinds of modern digital thermometer sensors, among the most common of which is a type called a ‘resistance temperature detector’ (RTD). This sort of thermometer works on the principle that the electrical resistance of metal changes with temperature.
Other digital thermometer sensor types include thermocouples and thermistors - these are both immediately recognisable as variants of digital thermometers with probes, although each type relies on related but distinct laws of thermodynamics for operation.
An RTD sensing element is effectively a subtype of thermistor. They’re built to include electrodes made from various types of suitable metals in a probe-style tip, each of which has a stable, repeatable and measurable resistance-versus-temperature relationship.
When an electrical voltage from a power source (often a simple battery in modern portable devices) is passed through these electrodes, the resistance it encounters is impacted by how warm or cool the metals are.
By measuring the resulting current flowing between electrodes of a specific metal (often platinum, but copper or nickel are also viable, if less versatile, options), an on-board chip can then convert this value into an extremely accurate reading of precise temperature at the element, and display it numerically on a screen. This is very commonly housed on the body of the tool itself, as seen in most LCD digital thermometers.

What are digital thermometers used for?
Digital thermometers offer an extremely wide range of uses in day-to-day professional and home applications. They provide accuracy and speed of temperature reading in almost any situation that a traditional thermometer would do, as well as being ideally suited to a great many scenarios in which liquid-in-glass versions would be unsuitable.

Industrial digital thermometers

Products intended for industrial use tend to be more ruggedly constructed and suitable for use in a range of potentially challenging or hazardous environments. They may be designed to fit with multiple different probe types, including thermistors and thermocouples, and will often include additional features such as countdown timers, rubberised IP-rated housings, backlit displays and non-sparking material constructions.
Common applications for industrial digital thermometers include HACCP environments, heat and hot water system testing, air conditioning and ventilation, refrigeration, manufacturing, and measurement of organic or oxidising surfaces.

Scientific digital thermometers

A scientific digital thermometer can play an extremely important role in all kinds of laboratory-based testing, experimentation, or product research and development.
They may form a crucial part of an incubator setup, for example, or be critical for fast and ultra-accurate readings across a very wide range of temperatures during product safety testing. In clinical trials, they might often need to be fully IP-rated for use in water baths, heating blocks and incubators, or able to run unattended for extended periods while logging or recording data.
Various sorts of scientific digital thermometers will include special features such as maximum and minimum temperature logging, on-board alarm systems, multiple readout displays or especially robust chemical and acid resistance

Medical digital thermometers