Bare Thermistors

Description

Bare thermistors are semiconductor devices that exhibit a change in electrical resistance with a change in temperature. They are highly sensitive components used for precise temperature measurements.

Working Principle

The working principle of a thermistor is based on its resistance-temperature relationship. Thermistors can be either negative temperature coefficient (NTC) or positive temperature coefficient (PTC). In NTC thermistors, resistance decreases as temperature increases, while in PTC thermistors, resistance increases with rising temperature. This property makes them useful for temperature sensing and control applications, as they provide a reliable and accurate means of measuring temperature changes.

Applications

Thermistors are commonly used in precision instrumentation applications such as hand-held meters and temperature gauges. They are also employed in medical thermometry, where accurate temperature readings are crucial, particularly around the human body temperature of 37°C (98.6°F) .

Advantages over other Thermistors

Thermistors offer several advantages, including their small size, high degree of stability, long-lasting nature, and high accuracy . These characteristics make them particularly suitable for applications requiring precise temperature measurements over a limited range.

Limitations

Thermistors have a limited temperature range and are not suitable for extreme temperatures . They also exhibit non-linearity in their resistance-temperature relationship, which can complicate their use in some applications . Additionally, thermistors are fragile and can be prone to self-heating, which may affect their accuracy .

Considerations

When considering the use of bare thermistors, it is important to account for their higher initial cost compared to other temperature sensors . Operating expenses may be influenced by their sensitivity to environmental conditions and the need for calibration to maintain accuracy. Durability can be a concern due to their fragile nature, and replacement and maintenance costs should be factored into the overall cost of ownership.