Match the reference to the application.
The readout supports the required 15 kΩ NTC characteristic. Include excitation timing, settling and update needs in the design review.
Review the specification →GUILCOR · NTC thermistors
15 kΩ NTC
Count the on-time, not just the nominal resistance.
A 15 kΩ NTC can be read intermittently to reduce average divider consumption. Estimate the electrical saving before choosing a sampling schedule.
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Understand the reference
What defines a 15 kΩ NTC?
15 kΩNominal resistance at 25 °C
NegativeResistance decreases as temperature rises
Curve + packageBoth must match the application
Higher resistance can reduce current in a scaled voltage divider, while switched excitation can reduce the time that current flows. Both choices need to be considered alongside settling and the required update rate.
A 15 kΩ NTC is a negative temperature coefficient thermistor with a nominal resistance of 15,000 Ω at 25 °C (R25). The value is a reference point, not a fixed resistance during use. Select the resistance–temperature characteristic together with tolerance, excitation and the completed probe construction.
SELECTION / YOUR APPLICATION
Is 15 kΩ NTC the right starting point?
Review 20 kΩ NTC alongside 15 kΩ NTC.
Compare the nominal resistance, reference temperature and full R/T characteristic. Matching at one temperature does not establish a compatible replacement over the operating interval.
Explore 20 kΩ NTC →Keep the complete specification together.
Keep the controller reference and the specified NTC curve together. Check tolerances, cable and probe construction rather than selecting by resistance or connector alone.
Prepare your enquiry →These links support a specification review. They do not establish interchangeable parts or availability of a complete assembly.
Application check
Estimate the benefit of duty-cycled excitation.
Tool input range: 0.1 to 60000
Tool input range: 0.1 to 60000
The example uses 3.3 V, a 15 kΩ pull-up and a 15 kΩ NTC at 25 °C. Change the on-time and period to compare continuous and average consumption.
Duty cycle
Current while on
Average divider current
Average sensor power
Enable JavaScript to calculate.
The model assumes an ideal switch and full supply voltage during each pulse. It excludes ADC, processor and switch consumption. Average sensor power does not predict peak temperature rise without a thermal model.
Model equationDuty = ton / period; Iaverage = Ion × duty
Leave enough on-time for the input to settle, and sample at a defined point after excitation starts. Verify switching transients and off-state leakage.
Operating principle
Read the characteristic, not just R25.
Illustrative resistance values
| Temperature | Resistance |
|---|---|
| -20 °C | 158,077.04 Ω |
| 0 °C | 50,430.91 Ω |
| 25 °C | 15,000.00 Ω |
| 50 °C | 5,382.27 Ω |
| 85 °C | 1,630.01 Ω |
| 100 °C | 1,046.28 Ω |
From resistance to temperature
The constant-β approximation uses R(T) = R25 × exp[β(1/T − 1/298.15)], with absolute temperature in kelvin. It is useful for comparing circuit assumptions; a real part may need its specified R/T table or Steinhart–Hart coefficients for the required interval.
For Steinhart–Hart, 1/T = A + B ln(R) + C[ln(R)]³. Use coefficients and resistance units supplied for the selected part. A coefficient labelled B here is not automatically the same as a thermistor’s β value.
The temperatures in this example are calculation points, not an operating-temperature rating. Confirm the element, cable, seals and assembled probe limits.
A low duty cycle can reduce energy use but also limits update rate. It does not prove adequate thermal response or system battery life.
Selection checklist
Specify the complete sensing assembly.
Electrical and thermal requirements
- R25 tolerance and the exact R/T curve, β interval or coefficients.
- Required temperature interval and complete measurement error budget.
- Measuring current, allowable dissipation and self-heating under the actual mounting conditions.
- Response time with its stated medium, flow and test method; no universal response time follows from R25.
- Ageing, drift and environmental qualification documented for the selected part.
Mechanical and installation requirements
- Element or assembled probe dimensions, sheath and contact arrangement.
- Cable length, insulation, connector and total two-wire loop resistance.
- Sealing, media compatibility, pressure and ingress requirements where applicable.
- Controller curve support, supply, input range, loading and acquisition timing.
- Calibration points and required documentation for the final assembly.
Wiring and measurement
Connect the sensor and account for the circuit.
Example two-wire divider
Supply → fixed pull-up Rs → measurement node
Measurement node → NTC → ground
ADC measures the node relative to ground
For an unloaded input, Vout = Vs × RNTC / (Rs + RNTC). In this arrangement, warming an NTC lowers the output voltage. The element has no polarity, although an assembled cable or connector can have a specified pin assignment.
Separate electrical and thermal errors
Lead resistance, leakage, finite input impedance and sampling transients can alter the measured signal. Measuring current also dissipates power in the element: P = I²R. The approximate steady-state self-heating rise is P/δ when the dissipation factor δ applies to the actual installation.
A robust coating or sheath can improve environmental protection while changing heat transfer. Validate the completed probe in its intended medium instead of carrying over the bare element’s response figure.
Application contexts
Where to evaluate a 15 kΩ NTC.
Remote environmental loggers
Choose a reporting rate that captures the temperature changes of interest.
Portable instruments
Budget the complete electronics, not only the sensor divider.
Long-duration monitoring
Check drift, environmental protection and calibration needs independently of average current.
Application examples are selection contexts. Suitability and any required certification depend on the identified reference and completed assembly.
Probe construction
Choose the installation format.
Match the sensing point, medium and mounting to the probe construction. These links explore construction families; confirm the required NTC characteristic when requesting a reference.
Frequently asked questions
15 kΩ NTC questions.
Does a 1% duty cycle mean the entire device uses 1% of the power?
No. Only the idealised divider contribution scales with duty cycle here. Processor, radio, ADC, regulator and leakage consumption remain part of the system budget.
Is every 15 kΩ NTC interchangeable?
No. Match R25, the complete curve and tolerances, then verify electrical excitation, construction, cable, environmental limits and controller configuration.
Can the example values replace a product datasheet?
No. The table and tool illustrate stated assumptions. Use the selected reference’s data, curve and test conditions for specification and validation.
What information should I send for a probe request?
Include the required R25 and curve, temperature range, allowable error, medium, mounting, dimensions, cable and connector, controller input and expected quantity.
Technical background: Manufacturer guidance on sensing and readout. Example calculations are educational models with the assumptions stated above.
GUILCOR / YOUR ENQUIRY
Define your 15 kΩ NTC enquiry.
Send the electrical reference and the installation details together. A nominal resistance alone does not define the right replacement or assembled probe.
Missing a reference or datasheet?
Send the component marking, equipment reference and any photographs or documents you have. These provide a starting point for identifying what must be confirmed.
The outline helps prepare your enquiry. Copying it does not send a request.
FOUR DETAILS THAT MOVE THE DISCUSSION FORWARD
01
Sensor and controller
Part number, nominal resistance and reference temperature, R/T data or specified β interval, tolerance and controller input.
02
Measurement conditions
Operating and peak temperatures, required accuracy and response target, measured medium and exposure to moisture or cleaning.
03
Assembly and connection
Probe dimensions, mounting or insertion, cable length and insulation, connector or lead termination. Attach a drawing or photo.
04
Project and validation
Sample and production quantities, target delivery, calibration or documentation needs, and the checks required before approval.