The History of Temperature Measurement and Temperature Sensing: A Chronological Overview and Trends in 2025
The temperature sensor market as all other sensor market have been witnessing steady growth for decades. Propelled by technological advancements in material science, IOT, AI, electronics and automation the market stood at approximately USD 7.7 billion in 2024, with projections pushing it past USD 8 billion in 2025.
At the heart of the overall large demand for especially the industrial thermal monitoring lies the ever increasing reliance on temperature sensors in process industries – particularly in oil & gas, followed by the usually strong contribution from automotive industry. Meanwhile, the rapid shift toward smart homes and intelligent building solutions, alongside growing demand in consumer electronics, adds further momentum to market growth.
Add to these the defence sector dynamics, and we have ourselves a vibrant industry of temperature measurements to look into, further in this blog.
Temperature Measurement – Methods, Sensors, Specifications
Temperature measurement has long been a fundamental pillar of scientific and industrial progress – an evolution that spans from simple mechanical tools to today’s highly sophisticated electronic systems. This transformation is a testament to humanity’s relentless drive for precision and efficiency in monitoring thermal conditions, a necessity across daily needs as well as industrial evolution. Let’s take a closer look at the key milestones in temperature sensor technology, examine their unique capabilities, and break down the current market landscape.
Mercury-in-Glass Thermometer: Description and Uses (1714)
A household name in temperature measurement, the mercury-in-glass thermometer was introduced in 1714 by Daniel Gabriel Fahrenheit and quickly became a standard tool across medicine, meteorology, and scientific research. In the infancy of meteorology as such, before Fahrenheit’s invention, some early liquid-in-glass thermometers existed in the 1600s already: these typically used alcohol or water rather than mercury, while the Farenheit’s invention was the “commercial model”For centuries, it was relied upon for its simplicity and accuracy, until concerns over mercury’s toxicity led to its decline. The design is straightforward – a glass tube with a mercury-filled bulb at one end. As temperature rises, mercury expands and moves up the narrow tube; as it falls, mercury contracts and descends. The movement aligns with a calibrated scale, providing an easy-to-read temperature measurement.
However, these thermometers have their limitations. Fragile glass construction makes them prone to breakage, and mercury’s freezing point of –38.83 °C limits their use in extremely cold environments. While once a widely accessible and low-cost option, today, safety regulations have restricted their availability. Depending on their type and application, vintage or specialty mercury thermometers can now range in price from $10 to over $100.
Thermocouples (1821)
When it comes to temperature sensors that have stood the test of time, thermocouples take the lead. Their durability in extreme thermal conditions, wide temperature range (-200 °C to ~2300 °C) , fast response time, and cost-effectiveness have cemented their place in industrial and scientific applications.
How do Thermocouples Work?
First introduced by Thomas Johann Seebeck, thermocouples work based on the Seebeck effect – a phenomenon where a voltage is created at the junction of two different metals when exposed to temperature differences. Their ability to handle extreme conditions while maintaining reliability makes them a go-to choice across industries, from manufacturing to research labs.
Bimetallic Thermometers (19th Century)
First introduced in the early 1800s, bimetallic thermometers quickly found their way into household appliances and industrial settings, thanks to their durability, simplicity, and cost-effectiveness. Their design relies on a bonded strip of two metals with different thermal expansion rates. As the temperature shifts, one metal expands more than the other, causing the strip to bend. This bending motion moves a pointer across a calibrated scale, giving a temperature reading. The appeal of bimetallic thermometers lies in their rugged construction, affordability, and ease of installation. They offer reasonable accuracy and operate without requiring any external power source – a practical solution for many applications. However, they do have some trade-offs. Their response time is slower compared to electronic sensors, and they may not be the best fit for high-precision applications. Over time, materials can experience creep, leading to slight calibration drift . That said, with prices typically ranging from $10 to $50, depending on build quality and application, they remain an efficient and budget-friendly choice for temperature measurement.
What Are Thermistors? (1930s)
In the 1930s, Samuel Ruben introduced the thermistor, a semiconductor-based sensor that has since become integral to digital thermometers and various electronic devices. Thermistors are renowned for their high sensitivity, compact size, and rapid response time, making them ideal for precise temperature measurements in controlled settings. However, they come with limitations, including a restricted temperature range, non-linear response, and the need for calibration. Additionally, thermistors can become less stable at elevated temperatures. Despite these drawbacks, their affordability – typically ranging from $1 to $10 – makes them a cost-effective choice for many applications.
Platinum Resistance Thermometers (RTDs, 1930s)
Initial development of platinum resistance thermometers began in the late 19th century, however the platinum Resistance Thermometers, also known as Resistance Temperature Detectors (RTDs) like the PT100 became prominent in the 1930s. They have since been valued for their high accuracy and stability in laboratory and industrial settings alike. RTDs measure temperature by correlating the electrical resistance of platinum with respective temperature changes. As the temperature increases, the resistance of the platinum element increases in a predictable manner.
High accuracy, stability, and a wide operating temperature range are some of the added values the customers go for, as this thermometers appear suitable for precision measurements.
Before commitment, one should be aware of the cost compared to other sensors and a slower response time that the RTDs are commonly known for as well as the requirements for additional equipment (e.g. bridge circuits and power supplies ) Prices for these can vary from $50 to several hundred dollars, depending on the sensor's specifications and application requirements.
Infrared (IR) Thermometers (1950s)
Infrared (IR) thermometers were introduced in the 1950s and became a groundbreaking method of temperature measurement by enabling non-contact readings. This innovation proved essential across various industrial and medical applications, particularly in scenarios where traditional contact methods were impractical or unsafe.
IR thermometers function by detecting the infrared radiation emitted by objects. A sensor within the device converts this radiation into an electrical signal, which is then translated into a temperature reading.
The ability to measure temperature without direct contact made IR thermometers indispensable for monitoring moving objects, hazardous materials, or environments with extreme conditions. Not so long ago, during the hight of the COVID-19 pandemic in the 2020, IR thermometers became crucial tools for rapid, non-invasive temperature screenings in public spaces, helping to identify individuals with elevated body temperatures efficiently.
How Accurate Are Infrared Thermometers?
While IR thermometers offer quick response times, their accuracy can be affected by factors such as emissivity variations. and environmental conditions like dust or smoke. Additionally, they tend to be more expensive than traditional contact thermometers, with prices typically ranging from $20 to $200, depending on the model and features. Despite these considerations, the non-contact measurement capability and rapid response of IR thermometers have solidified their role as a revolutionary tool in temperature measurement.
Liquid Crystal Thermometers (1960s)
Another honourable mention for the thermometer universe is the liquid crystal thermometers first introduced in the 1960’s – these provided a visual method for temperature measurement, finding use in medical diagnostics and novelty items especially.
How Do Liquid Crystal Thermometers Work?
These thermometers use liquid crystals that change colour in response to temperature fluctuations, providing a visual representation of temperature changes. Getting a clear visual indication of temperature changes as a Non-invasive and easy to use method is highly valuable for many end user (considering that the prices vary from $5 to $20), however if your priorities are accuracy, wide temperature range resistance to environmental conditions – then perhaps this is not the thermometer for your needs.
Fiber Optic Temperature Sensors (1970s)
As optical technology advanced in the 1970s, fiber optic temperature sensors emerged, offering solutions for environments where traditional sensors were inadequate.
These sensors use light signals transmitted through optical fibers to measure temperature. Changes in temperature affect the properties of the light signal, which is then analyzed to determine the temperature.
Some of the main Industries & Applications for Fiber Optic Temperature Sensors:
- 1. Power & Energy – Used in power grids, transformers, and high-voltage substations to monitor temperature and prevent failures. Key Benefit: Immune to electromagnetic interference, ideal for high-voltage environments.
- 2. Healthcare & Medical – Essential in MRI machines and other medical imaging devices where traditional sensors fail due to EMI. Key Benefit: Safe for use in sensitive medical environments.
- 3. Oil & Gas – Deployed in downhole drilling, pipelines, and refineries to ensure safety and operational efficiency in hazardous conditions. Key Benefit: Works in extreme environments and explosive-risk areas.
- 4. Aerospace & Defense – Used in aircraft, spacecraft, and military applications for temperature monitoring under extreme conditions. Key Benefit: High precision and reliability in mission-critical systems.
Fiber Optic Temperature Sensors do have higher cost (Typically range from $500 to several thousand dollars) and complexity compared to traditional sensors, they require specialised equipment for signal interpretation, often team of professionals to service the system itself, at the same time, when the RoI is validated, these can prove to be the perfect solution for hips of tasks.
Digital Temperature Sensors (1980s-1990s)
With the rise of microelectronics in the late 20th century, digital temperature sensors became common, offering precise readings for various applications.
Digital temperature sensors are integral in industries such as automotive, healthcare, industrial automation, and consumer electronics. They provide precise temperature monitoring for applications like engine and battery management in electric vehicles, patient monitoring devices, process control in manufacturing, and thermal regulation in smartphones and HVAC systems.
How Do Digital Temperature Sensors Work?
These sensors use semiconductor devices to measure temperature and provide a digital output, often integrated into microcontrollers.
The advantages of digital temperature sensors are high accuracy, easy integration into electronic systems, real-time data transmission, and low power consumption, making them ideal for smart devices, industrial automation, and medical applications. However, they have higher costs, limited temperature range compared to some analog sensors, and susceptibility to electromagnetic interference, which can affect performance in certain environments.
MEMS (Micro-Electromechanical Systems) (2000s)
Micro-Electro-Mechanical Systems (MEMS) technology has its origins in the early 1960s, following the invention of the integrated circuit. Initially, MEMS devices were primarily designed to measure parameters such as pressure and motion. However, it was in the 2000s that MEMS technology saw significant integration into various industries, including temperature measurement applications.
The advantages of MEMS temperature sensors include their compact size, low power consumption, and high sensitivity. These attributes make them ideal for integration into devices, boosting their usability for precise temperature measurements in applications ranging from consumer electronics to industrial automation.
However, MEMS temperature sensors also have certain limitations. They may exhibit nonlinearity and are often limited to specific temperature ranges. Additionally, their performance can be affected by environmental factors such as humidity and mechanical stress, which may impact their accuracy and reliability in certain applications.
Today also, MEMS temperature sensors keep offering significant benefits in terms of miniaturization and efficiency, it is essential and known that one should consider their limitations and the specific requirements of the intended application to ensure optimal performance.
MicroWire Sensors
Representing a sensor company ourselves – RVmagnetics comes with agenda of R&D of our MicroWire technology, which, among other things can be utilised as a passive temperature sensor. Using a measurement method based in magnetic principles – MicroWire technology needs no direct contact, can survive extreme temperatures, and measure in high accuracies (data sheet). With the right R&D direction and effort MicroWire tech is already proving its validity for thermal management systems from BTMSs to Composite Manufacturing processes.
These and other developments in the space of temperature measurement highlight the ongoing efforts in enhancing thermal sensing and management technologies as such to improve performance, safety, and efficiency be it in electric vehicles, healthcare, aerospace, defence, or consumer goods that not only highly benefit from accurate thermal measurements, but they wouldn’t be able to get where they are without the luxury of accurate thermal data. Our approach is novel especially in the sense of commercialization, innovative approach to not-yet-existent solutions to both long-stagnating and novel challenges in various industries, and we strive for wider adoption of our solution.
Conclusion
Oren Harari once remarked, „Electric light does not come from the constant improvement of candles.“ While it may sound like a clever quip, the invention of the light bulb truly exemplifies disruptive innovation – born from breakthroughs in materials like tungsten, advancements in glass manufacturing, and the emergence of electricity and power networks. It was not a linear improvement but a convergence of multiple domains that redefined illumination.
The same principle applies to sensor technology. As we've explored throughout this article, the evolution of temperature measurement has transitioned from century-long cycles to a pace where new types of thermal sensors emerge nearly every decade. These advancements are never isolated – they're the outcome of persistent R&D, combining innovations in materials science, electronics, software, and semiconductors.
Sensors, by nature, are interdisciplinary. Developing a new class of sensors is a long-term journey, requiring not just technical ingenuity but also the integration of knowledge across fields. At RVmagnetics, our MicroWire technology is part of this ongoing trajectory. It reflects decades of groundwork and innovation, and we're committed to ensuring it becomes a widely adopted solution across industries.
