Verify the Meaning of “100 Ω”
A 100 Ω NTC thermistor has a resistance that decreases as temperature rises, but the nominal resistance value is only meaningful with its reference temperature and exact part number. Do not assume the value is specified at 25 °C unless the manufacturer’s datasheet says so. Parts with the same nominal resistance may have different R/T curves, tolerances, beta intervals, packages and assembly limits.
Confirm Whether the Part Fits the Measurement Task
For temperature measurement, obtain the exact resistance–temperature table or curve and check its guaranteed tolerance across the required span. Confirm the controller’s measurement range and conversion support. A nominal value alone does not establish sensitivity, accuracy, temperature limits, response time or the intended application.
TDK’s NTC thermistor technical information explains the relationship among R/T characteristics, resistance tolerance and beta values. Use the selected ordering code’s datasheet for design limits.
Check Circuit, Self-Heating and Assembly
Review the readout together with the element. Verify excitation, reference-resistor tolerance, ADC or controller input, wiring, conversion method and resolution across the full range. Keep measurement power within the manufacturer’s recommendations and account for heat transfer in the installed medium, as self-heating can affect the sensed temperature.
If the thermistor is supplied as a probe, define the sensing location, contact or immersion, housing, cable, connector and installation environment. Mounting and thermal contact can alter the complete probe response. Our NTC chart guide and circuit design guide cover curve and readout considerations.
Validate the Finished Sensor System
Check rated operating and storage limits for the element and completed assembly. Compare the production probe and readout with a suitable reference at several stable points over the required range. Record the sample, setup, equilibrium conditions, reference uncertainty and acceptance limits. Determine calibration or correction needs from the application rather than assuming nominal resistance defines system performance.
Prepare an OEM RFQ
Provide the part number, nominal resistance and reference temperature, R/T data, tolerance, operating span, controller input, probe drawing, materials, cable and connector, medium, quantity and annual volume. Ask the supplier to confirm which characteristics apply to the selected element and which depend on the finished probe. For a finished probe configuration, review the custom NTC thermistor probe assembly information. Review the NTC sensor range or request an OEM quotation with the target curve and installation details.
