Sensing Temperature with NTC Thermistors

Temperature sensors using NTC thermistors are built from sintered semiconducting ceramic material. Such materials contain a mixture comprising several metal oxides. The specialty of these materials is they possess charge particles, which allow current to flow through the thermistor, and display large changes in its resistance value even when the change in temperature is rather small. The manufacturing process allows standard NTC thermistors to operate effectively in the temperature range between 50 and 150°C, with glass-encapsulation type of thermistors going up to 250°C.

Thermistors come in a large variety of sizes and styles. These include glass encapsulated, customizable probe assemblies, surface mount types,, disc types, and chip styles. The large variety is necessary as individual attributes of each style gives them the ability to perform effectively in several different industries, while adapting to various and different application requirements.

For instance, industries using NTC thermistors for measuring temperature include telecommunications, medical, healthcare, military, aerospace, automotive, industrial, HVAC, among many others. On the other hand, applications for NTC thermistors cover time delay, volume control, circuit protection, voltage regulation, temperature control, temperature measurement, temperature compensation, and more.

Now, the availability of precision interchangeable NTC thermistors eliminates the necessity of individual calibration for each thermistor. Capable of accuracies of ±0.05°C, the interchangeable thermistors are now gaining popularity as industry standard. Their standard resistance values usually range from 2.25 kilo-ohm to 100 kilo ohm, with temperature coefficients of -4.4% per °C or -4.7% per °C.

Interchangeable NTC thermistors offer extreme accuracy when sensing temperature. This makes these versatile sensors an excellent choice for use in industries focussing on temperature measurement and control. These industries include, among others, aerospace, HVAC, automotive, industrial, and medical. Applications for interchangeable NTC thermistors include temperature sensing, temperature measurement and control, temperature measurement, and control.

Using interchangeable NTC thermistors in the industry offers several benefits and features. These include beta of 3435 K to 4143 K, RoHS compliance, dissipation constant of 1 mW/°C, fast thermal response times, wide range of ohmic values, a thermal time constant of 7 secs, and fast measurement times. Aging is slow as these NTC thermistors show less than 1% change in resistance even after a span of 10 years. That means, there is no need to recalibrate the system when replacing the thermistor. This certainly reduces operating costs and system downtimes.

Glass encapsulated NTC thermistors are a special breed that are hermetically sealed. This allows the micro-sized sensors to eliminate reading errors from moisture penetration. As they are hermetically sealed, they function effectively in extreme conditions of temperature, pressure, and other severe environmental conditions. The extreme operating conditions allow glass encapsulated NTC thermistors to target markets such as industrial, automotive, medical, and HVAC.

Glass encapsulated NTC thermistors are good for applications involving outdoors such as infrared lighting systems, medical such as those relying on airflow/respirators, industrial such as those including monitoring of terminal temperatures of battery packs while charging, common household appliances such as in coffee makers, ovens, and refrigerators, HVAC such as for temperature measurement and control.

Apart from greater accuracy and faster response times, Glass encapsulated NTC thermistors offer high precision resistance and beta value with a huge operating temperature range.