Amphenol Advanced Sensors is expanding its Thermometrics family of precision temperature sensors with the A266T. This miniature NTC thermistor in a 316 stainless steel housing is designed for accurate continuous and intermittent temperature measurement. It combines tight measurement tolerances, compact dimensions and mechanical protection of the sensing element, making it well suited for demanding medical and laboratory applications.

The A266T can be used in applications such as in vitro diagnostic analyzers, blood analysis equipment, dialysis systems, surgical instruments and skin-temperature sensors for wearable devices.

 

High accuracy in the medical temperature range

The A266T is a 10 kΩ NTC thermistor at 25°C with a Beta 25/85 value of 3969 K. The sensor offers very tight temperature tolerances in ranges particularly important for medical measurements:

• ±0.05°C from 35 to 39°C,
• ±0.075°C from 39 to 42°C,
• ±0.10°C from 20 to 45°C,
• ±0.15°C from 0 to 50°C.

The full operating temperature range is -40°C to +105°C. Thermistor sensitivity at 25°C exceeds -4%/°C, enabling even small temperature changes to be detected clearly.

 

Compact stainless steel probe

The sensing element is housed in a cylindrical 316 stainless steel sleeve with a maximum diameter of approximately 2.16 mm and a length of approximately 10.16 mm. Electrical connection is provided by twisted silver-plated copper leads with TFE insulation, supplied as standard in lengths of at least 24 inches.

The housing provides high mechanical resistance and protects the thermistor from contact with liquids. However, the standard A266T is not intended for full immersion – the wire exit at the rear of the probe should be protected from conductive liquids. The reference time constant is approximately 1.6 s in stirred oil and 26 s in still air.

 

Potential applications

In IVD analyzers such as PCR thermocyclers, hematology analyzers and clinical chemistry systems, the A266T can support stable temperature control of samples and reactions, while its compact size facilitates integration into space-constrained measurement assemblies. In dialysis equipment and other systems handling fluids, its accuracy and stainless steel housing can support monitoring of critical medium temperatures, provided that the rear section of the probe is properly protected from liquid ingress. The sensor can also be used in medical equipment washing and disinfection processes where maintaining a defined water or solution temperature is important. The manufacturer also identifies skin-temperature sensors and wearable devices as target applications, where compact dimensions and high accuracy around body temperature are key advantages.

 

 

Key A266T specifications

 

Parameter	A266T
Sensor type	NTC thermistor
Nominal resistance	10 kΩ at 25°C
Beta 25/85	3969 K
Accuracy 35–39°C	±0.05°C
Accuracy 39–42°C	±0.075°C
Accuracy 20–45°C	±0.10°C
Accuracy 0–50°C	±0.15°C
Operating temperature range	-40°C to +105°C
Housing material	316 stainless steel
Max. probe diameter	0.085 in / approx. 2.16 mm
Probe length	0.400 in ±0.015 in / approx. 10.16 mm
Lead wires	#30 AWG, silver-plated copper, TFE insulation
Time constant	approx. 1.6 s in stirred oil; 26 s in still air
Compliance	RoHS

For projects requiring different parameters, the manufacturer offers custom variants including nominal resistance values from 2252 Ω to 100 kΩ, different tolerances, lead lengths and wire types, modified R/T characteristics, and controlled mechanical dimensions.

Information for medical applications

 

Amphenol Advanced Sensors states that no biocompatibility or clinical testing has been performed on these products. The OEM or end user is responsible for ensuring that the final device complies with all applicable legal and regulatory requirements.

 

 

For technical questions and quotation requests, please contact us by phone at +48 58 662 05 79 or by email at [email protected]

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Source materials

• Product Spotlight – A266T NTC Thermistor (AS-930-318B, 05/2026) – PDF

• Datasheet – A266T NTC Thermistor (AS-920-833A, 07/2026) – PDF

• Application Spotlight – IVD Analyzers (AS-930-321A, 04/2026) – PDF

• Application Spotlight – Fluid Temperature Sensors for Medical Applications (AAS-930-293A, 02/2022) – PDF