| Epoxy-coated NTC bead | Many standard designs are used over approximately −50 to 150°C; the specified limit depends on the sensor construction and lead materials. | Small and easy to mount, but the bead and leads need mechanical protection. Use a suitable thermal interface and avoid placing the sensor where it measures surrounding air instead of the target. | NTC resistance decreases as temperature rises. Use the supplied resistance-temperature table or coefficients; a single-point check does not verify accuracy across the full range. | Protect the coating and lead junction from moisture, chemicals, abrasion, and sustained operation near the maximum rated temperature. | Appliances, HVAC equipment, battery monitoring, and general-purpose temperature sensing. |
| Glass-encapsulated NTC bead | Some designs support operation to around 250–300°C, but the actual range is model-specific and must be confirmed from the datasheet. | The glass body can be fragile. Provide strain relief for the leads, and check that the mounting method and surrounding materials tolerate the operating temperature. | Use the manufacturer’s resistance-temperature curve and the specified test current. For critical work, compare readings at multiple points against a traceable reference. | Glass sealing can offer strong protection against moisture and contamination, but impact, lead stress, and thermal shock can still cause failure. | Hot surfaces, industrial equipment, and other applications needing a compact sensor with a higher temperature capability. |
| Sheathed NTC probe | Varies substantially with the sensing element, sheath, cable, seal, and probe construction; use the complete assembly’s rated range rather than the element’s range alone. | Insert or clamp the probe to ensure good thermal contact. Select a sheath compatible with the process, and check immersion depth, response time, pressure, and sealing requirements. | Probe assemblies may be supplied with a specified tolerance or calibration. Calibrate the assembled probe and readout together when system-level accuracy matters. | Check for corrosion, cable damage, seal degradation, and drift from repeated thermal cycling. A protective sheath can improve durability but may slow response. | Liquid or air temperature measurement, process equipment, and installations requiring a robust, mountable sensor. |
| Surface-mount NTC | Depends on the element, substrate, adhesive, and wiring; the mounting materials can set a lower limit than the thermistor itself. | Place it firmly against the surface using a suitable adhesive, clip, or thermal interface. Insulate the sensor from ambient air when the goal is to measure the surface temperature. | Calibration should reflect the installed arrangement because contact pressure, adhesive thickness, and heat flow can affect the reading. | Adhesive aging, vibration, surface contamination, and repeated expansion and contraction can loosen the sensor or change thermal contact. | Electronics, motor housings, heat sinks, and equipment where surface temperature is more relevant than air temperature. |
| PTC switching thermistor | Designed to change resistance sharply near a specified transition temperature; it is generally not intended for accurate continuous measurement across a broad range. | Mount close to the component or location that needs overtemperature protection. Ensure reliable thermal contact and keep it within its specified electrical and temperature limits. | Choose the specified transition temperature and switching behavior. Verify the trip point and circuit response in the assembled device rather than treating it as a linear temperature sensor. | Confirm the rated switching cycles, reset behavior, and environmental limits. Electrical self-heating and poor thermal coupling can affect operation. | Overtemperature protection, motor winding protection, and resettable thermal switching circuits. |