Thermistors are special solid temperature
sensors that behave like temperature-sensitive resistors; hence their name is
a contraction of "thermal" and "resistor". They are mostly very small bits of
special material that exhibit more than just temperature sensitivity.
During the last 60 years or so, only ceramic materials (a mix of different metal oxides) was employed for production of NTC thermistors. In 2003, AdSem, Inc. (Palo Alto, CA) developed and started manufacturing of NTC thermistors made of semiconductors materials, Silicon and Germanium, having both higher and lower temperature measurement capabilities and better overall performance than any ceramic NTC thermistors.
Thermistors are highly-sensitive and have very reproducible resistance Vs. temperature properties. They are used inside many other devices as temperature sensing and
correction devices as well as in specialty temperature sensing probes for
commerce, science and industry.
Thermistors typically work over a relatively small temperature
range, compared to other temperature sensors, and can be very accurate and precise
within that range, although not all are. Some, like the semiconductor types have expanded the reach of these little devices.
are some links to website sources of thermistors, both Positive Temperature Coefficient
(PTC) and Negative Temperature Coefficient (NTC) -- see comments for which vendors
offer which types.
The general rule of thumb is that most vendors default offerings
are NTC, unless they say otherwise.
Like many things on the
Web, it is a bit of underedited data, but edited enough to make it useful to some,
Featured Link AdSem, Inc.
Supplier of novel Si and Ge NTC thermistors with unique performance capabilities from below normal cryogenic to 500 °C
Supplier of novel Si and Ge NTC thermistors with unique performance:
the highest operating temperature, the widest interchangeability
temperature range, the highest thermosensitivity, the smallest
size and universal R-T dependence.
AdSem, Inc. is only company in the world that offers NTC thermistors
with the best performance for any temperature range between 10mK
and 500 °C. They also offers the smallest semiconductor RF and
low-temperaturre IR bolometers.
Manufacturers of custom and standard temperature sensing probes and assemblies
as well as PTC and NTC thermistors. ATP supplies products to the HVAC,
Appliance, Food Service, Pool & Spa, Medical and Electronics Industries
from St. Marys, PA
Offers both NTC and PTC devices and four downloadable applications notes
in pdf covering temperature measurement, temperature compensation circuits
and calculating the temperature coefficient of a thermistor as part of
their NTC Thermistor Application Notes
TempLine Sensor Array of point sensors either specialized, thermistor
or RTD in waterproof cables complete with data acquisition device.
Sensors(USA & Ireland)
BetaTHERM manufactures high precision NTC thermistors and temperature probe
assemblies. Products include leadless chips, discrete thermistors SMDs,
glass thermistors,standard and custom temperature probes.
Cornerstone Sensors specializes in NTC thermistor technology, offering
a diversity of product configurations to meet a multitude of design and
EPCOS, Inc.(USA & Germany)
Thermistors (few words-lots of products)
GEC Instruments (USA)
Precision temperature instruments feature highly stable thermistor probes
with overall system measurement accuracy of ±0.001°C over
the range of -5 to 60°C. Resolution is ±0.0002°C or better.
These units are available with single or multiple inputs and they connect
to a PC via RS232 serial port or USB. Instruments are accompanied by
a versatile Windows software package for display, plotting and logging
of temperatures. GEC Instruments also provide custom thermocouples, custom
thermocouple calibration and RTD probes & data loggers.
Provides the Model HI 9040, a hand-held digital thermometer that uses an
interchangeable probe with thermistor sensor to deliver fast response and
high accuracy. for the range:-58.0° to 302°F (-50.0 to 150.0°C).
A wide variety of interchangeable probes for applications such as air,
liquid and penetration are available.
Makes Heavy Duty Temperature Controllers for Heat Lamps and Electric Radiant
Infrared Heaters with thermistor temperature sensor included.
Kele & Associates
A manufacturer of specialty sensors and controls covering a wide range
of HVAC uses. Also a unique website with a virtual treasure of useful
technical information on thermistors and other topics (e.g." The
Truth about NIST Traceability") written in plain language worth
just about any engineer's visit. Also the home of the Kele calculator
for converting between units for a number of variables including four
different temperature scales, much like our own desktop temperature conversion program, but this one operates live on the web!
Customized OEM Temperature Sensors: Thermistors- VARIETY OF CURVES
Standard Thermistors such as 15KOhm @25°C, Type: NTC , Curve:
Fenwall Curve 16 and links to more.
Mitsubishi Materials Corporation, a world leader in the production for ceramic
electronic components and advanced electronic materials has variety of
unique Thermistor,Thermistor sensor,Temperature sensor,Chip thermistor,NTC
thermistor,Surge absorber and more.,
Mostly PTC thermistors and electronic capitors, but also a uniques series
of technical notes in short story form called the Nichicon Mini Story;into
its second series on Units.
Oven Industries For 40 years, Oven Industries has specialized in the design and manufacture
of custom electronic controllers and sensors. Along with their custom design
services, they provide standard temperature sensors and controllers for
heating and cooling applications including those that use thermoelectric
modules (Peltier modules).
Temperature Measurement and Logging
Their Model TH-03 allows up to 3 channels of temperature to be recorded
onto a PC. It uses precision thermistors to give an accuracy that was previously
only obtainable using expensive platinum PT100 sensors. They also make
similar devices for logging multi-channel temperature readings from thermocoups
Precision Measurement Engineering
Is an instrumentation development and manufacturing company based in southern
California. We manufacture instruments and sensors for high resolution
measurement of electrical conductivity, temperature, fluorescence, turbidity,
and PAR concentration in water. These instruments are designed for laboratory
and field use.Their products have been used in research institutions worldwide
NTC Thermistors, RTDs, and Humidity Sensors available in
standards or custom probes. Precon also designs and builds controllers
and can provide turnkey sensing and control solutions
Inc. (USA) Boise, Idaho
At the web address www.thermistor.com< Special surface mount thermistors
in both PTC and NTC as well as military grade, special NTC probes for Gas/Air/Liquids
and surface temperature measurement.
Selco Products Co..(USA) Anaheim, CA
Selco's high-quality, high-performance negative temperature coefficient (NTC) thermistors include epoxy coated interchangeable, surface mount, DO35 glass, and thin film models. Custom options in probes, configurations, leads, and connections are available. For more information, go to: www.selcoproducts.com/cfm/ntc_thermistor_toc.cfm
Inc.(USA) Fairfield, New Jersey,..
"Your Design Partner for Thermistors and Temperature Assemblies"
Systems Inc (USA) Brevard, North Carolina,
Standard and Custom Sensors for Speed, Motion and Temperature - Cabling
more on their Directories. NOTE:Vendors
can list themselves there at no cost-IT'S FREE and EASY!
Thermik (USA & Germany)
Manufacture thermal protectors in the US.
O-Disc NTC and PTC Thermistors(USA)
Therm-O-Disc NTC thermistors offer economical, reliable and accurate solutions
to those applications requiring more extensive sensing than the one or
two temperature points typically offered by a bimetallic thermostat. Therm-O-Disc
has been custom engineering and marketing polymeric PTC circuit protectors
for over 15 years. Their product provides solid state protection against
over temperature and/or over current conditions.
Make a wide variety of NTC Thermistors in many forms from surface mount
to probe assemblies as small as 0.017" (~0.5 mm) max o.d.. Also supplier
Specialty thermistors for electronics and other uses from one of the world's
largest makers of passive electronic components.
Electronics, Inc (USA)
Manufacturers of specialized temperature sensors and controllers for laser
diode assemblies and related electronics temperature control equipment
used in R&D and production.
Component Corp (USA)
NTC Inrush Current Limiters, Surface Mount Products, Linear PTC Thermistors
(Over Temp Protection/ Compensation), Switching PTC Thermistors (Over Temperature
Protection) NTC Solid Body Thermistors (Temp Measurement/Compensation)
and NTC Thick Film Thermistors (Temp Measurement/Compensation)
Different NTC Thermistors, e.g. SMALL BEAD & GLASS PROBE NTC Thermistors,
-50°C to +300°C. GLASS ENCAPSULATED Thermistor Probes Series
0° to 70°C. INTERCHANGEABLE WAFER Thermistors to 150°C.
, Tolerances to 0.1°C, and many different types of thermistor
assemblies. Also supply Data-Recorder / Data-Logger, (1 to 16 Channels)
for Temperature, RH, voltage, current and pressure with Software
and Sensor selection. and miniature two channel Data Logger for
temperature measurements. Range: -30°C to +75°C (+120°C
at external Sensor) with sampling rate of 10 Sec. to 20 Min.
Supply a wide variety of electronics components and sensors and control
products especially NTC Thermistors and Temperature sensing probes as
well as Pt and Mo RTDs.
noteThe Temperature Sensors
Directories Web Site, a companion site set up to enable direct inputs from
temperature sensor users and makers. Vendors, do visit there. Sign in and enter
your own company data, product and service offerings and news-It's been Improved!
Users can post reports & reviews of companies, news, products and services.
Note that inputs are moderated for propriety and excess zeal! Best of all, it
is freely available and "self service".