ATC Semitec

By definition – NTC thermistors are highly sensitive thermal resistors that respond very quickly to rapid changes in temperature- the word thermistor itself is a contraction of “thermal” and “resistor”.

NTC thermistors are so-called because of the resistance of an NTC decreases with an increasing temperature and their R-T (Resistance – Temperature) is very accurately defined. The R-T accuracy combined with the fast rate of change (compared to RTDs and thermocouples) makes them ideal to incorporate in electronics control circuitry

ATC Semitec’s range of glass NTC thermistors includes NT-4 radial glass beads, ATCD series DO-35 diode style NTCs and FT thin film thermistors, suitable for accurate high temperature control up to 350°C.

Our range of high precision NTC thermistors enable engineers to accurately control operating temperatures which is critical in many product applications within the automotive, home automation and medical device industries.

Precision thermistors are highly accurate with 0.5% resistance tolerances (or better) offering long term stability and control; their RT curve interchangeability eliminates the need for individual circuit calibration.  Available with ±0.2°C (0-70°C) accuracy or better, they can operate up to 150°C and so are also suitable for use in automotive applications. With a wide range of R25 resistance values, B values and format types, please call us about specific requirements.

Flexible Thermistors are NTC thermistors which have flexible insulation to help simplify product assembly or provide unique monitoring solutions. Using flexible thermistors will help to speed up assembly and thus minimise production handling costs.  Their small bead size give faster, accurate sensing and/or temperature control in numerous domestic and commercial applications.

SMD NTC chip thermistors have been developed as a surface-mount temperature sensor option and offer very cost-effective, reliable temperature control for printed circuit applications. These are particularly useful where  space is limited and with chip sizes down to 0201, they can be used in the tightest of applications and closer to the heat source

Available with a wide range of resistance values, B values and tolerances down to ±1%, they are suitable for applications such as the temperature measurement and temperature compensation of fire detectors, wearable devices, lighting controls and smart meters.

We can also supply bespoke values for  volume applications, so please contact us for specific queries.

Temperature sensors come in all shapes and sizes. Our different types vary from  simple plastic encapsulations for air-sensing applications to sophisticated leaf-spring designs, offering precision control of surface temperatures up to 250°C. Fast response temperature sensors utilising exposed bead NTC thermistors or thin wall tubes, help to control rapidly changing temperatures in air or fluids up to 200°C.

Single-insulated 103AT-11 and double-insulated TPE encapsulated temperature probes use 0.5% tolerance NTCs to ensure accurate temperature control to ±0.15K. These thermistor sensors are waterproof to IP68 and are available with or without terminals to suit your application needs. We also supply brass, copper or stainless steel housings (with or without fixings) to provide robust sensors that can be used in numerous environmental conditions.

One of our latest innovations is the F-micro miniature thermistor sensor which was developed for use in medical applications, such as catheters. Utilising smaller and smaller FT thermistors, the F-micro can now be supplied in tubes as small as 0.28mm, with a time constant as fast as 20ms. With further innovation, ever smaller sensors will be available for future applications, allowing very accurate temperature measurement where it wasn’t previously possible.

These sensors are designed for temperature control and monitoring of liquid/coolants where a very fast thermal response is essential. This, combined with a high thermal accuracy, ensures accurate temperature control of the liquid/ coolants to help maximise efficiency.

ATC Semitec stock a number of immersion, inline and clip-on temperature sensors where the NTC thermistor is situated in the very tip of the sensor. This design reduces the thermal path to the thermistor and minimises the response time, allowing for faster temperature control. Screw threaded boss designs, surface sensor fixings for pipes and simple push-fit/clip-in versions are all available with industry standard connector options or flying leads if preferred.

Some temperature control applications, such as domestic showers and instant water heaters, require a very fast thermal response of 1 second or less. This is to maximise the thermal efficiency of the device and avoid potential scalding of the user.

In response to this, ATC Semitec stock a number of very fast-response temperature probes where the NTC thermistor is situated in the very tip of the sensor. This reduces the thermal path to the thermistor and thus minimises the thermal response time. Response times can be further accelerated by using our thin wall tip or exposed NTC sensor.

Our standard sensor  assembly packages include: screw threaded bosses, bayonet fittings and push-fit/clip-in designs – all of which are available with flying leads and/or industry standard connector options.

For an ultra-reliable, waterproof temperature sensor with IP67 or IP68 integrity, then look no further than our range of TPE-encapsulated sensors.  These over-moulded NTC Thermistor probes use the same TPE moulding material as the integral lead-wire’s insulation.  By using double-insulated or single-insulated TPE cable, a true waterproof seal is created by the fusion of the two insulating materials making the sensors suitable for direct immersion in the media being measured.  This makes them ideal for refrigeration, air-conditioning, underfloor heating and heat pumps, solar and other green energy solutions.

Our IP67 and IP68 waterproof sensors can be fitted with any NTC Thermistor from our AP-2, AT-2, ATCD, NT-4 or SP series ranges.  From this very wide range of R25 and B values, we can match or fine-tune the sensor specification to meet your application requirements.  Also Pt100, Pt500 or Pt1000 RTD elements are now available in IP67 or IP68 versions. ATC Semitec now stock the YAGEO NEXENSOS EC3032 an IP68 rated RTD temperature sensor

Cable lengths can be supplied from 100 mm up to 10 metres long so that you have a single uninterrupted sensor cable helping to ensure product integrity.  Metal tips or stainless-steel housings can be added to help increase their physical robustness where an abrasive sensing environment could be encountered.  For even harsher environments, shielded cable options and armoured cabling is also available.

As we age and demands on our personal health increase from day-to-day, the need for new medical device solutions increases accordingly too.  Our range of NTC Thermistor sensors helps to meets those needs and also those of future medical device designs.

Semitec ET series Thermistors are small, fast-responding bead NTCs and have long been associated with clinical thermometer applications.

More recently, the Semitec F micro miniature sensor is fast becoming an industry standard used in ablation and various other catheter types.  The F micro sensor uses our unique thin-film FT thermistor as its sensing element and smaller and smaller iterations of the FT now means that a 0.28mm diameter temperature sensor is possible – the thermal time constant for this size of sensor is as fast as 20 milliseconds!

The FT Thermistor is an 0402 (or smaller 0201) size thin-film NTC sensor on a 150micron ceramic substrate that helps to produce an exceptionally fast thermal response.  As well as being used in various fast-response temperature sensors, it is also now used as the main temperature sensing element in diabetic patch monitors.  Future FT designs will be even smaller allowing for other minimally invasive applications as well as potentially internal organ monitoring.

ATC Semitec is the key UK & Irish distributor  for the extensive range of platinum RTD sensor elements from YAGEO Nexensos GmbH, from Pt100 to Pt2000.

Based in Hanau (near Frankfurt), Heraeus invented the very first platinum sensor in the early 1900s, initially developing wire-wound technology and then later introducing thin film Pt100 elements in the 1970s.

These thin film platinum elements could be readily mass produced which helped to lower the unit cost.  This meant that platinum sensors found their way into a wider range of applications that benefited from their linearity, precision and very stable characteristics.  These applications vary from e-vehicle battery sensors and 3D printer heads to aspirating smoke detectors and e-cigarettes.  YAGEO are constantly striving to develop their sensors for new and exciting applications and still lead the world today in thin film platinum sensor technology.

YAGEO Nexensos manufacture a wide selection of platinum temperature sensors for diverse industries, measuring process temperatures, regulating heating systems and compensating for temperature fluctuations at component level.

The thin film RTD elements were originally manufactured with lead-wires for PCB mounting and use in sensor assemblies.  As surface mount technology rapidly developed, the need for SMD Pt100 or Pt1000 sensor elements led to the development of various SMD formats.

1206 chip sizes were the first to appear but as electronic components got smaller, the chip sizes of Pt elements shrank accordingly so that today we can offer 0805 and 0603 Pt100s and Pt1000s as well – 0402 size chips will inevitably follow shortly!

YAGEO Nexensos’ wired Pt-RTD sensor elements are designed for either PCB mounting or for use in temperature sensor assemblies.  Our wide range of sensors, available from UK stock, ensures that there is a suitable product for your application.

Our M-series RTD sensor elements are the best choice for general applications, being suitable for use from -70°C to +500°C.  Pt100, Pt500 and Pt1000 options are available on chips as small as 2mm x 2mm square with even smaller formats now offered.

YAGEO Nexensos not only supply a wide range of platinum RTD elements but also temperature sensor assemblies in various formats.  Of all the numerous sensor designs, two of the most interesting are as follows;

EC3032 temperature sensors are high integrity, encapsulated RTD sensors primarily designed for use in e-vehicle e-motor applications.  Their small size and IP68 insulation rating makes them ideal for use in the e-motor stator windings and they are also impervious to varnish ingress and other fluids such as oil or grease.  Using a Pt1000B element as standard, the 410mm PTFE long leads make this a very versatile sensor that can be used from -50°C to +200°C.

Our PCB RTD temperature sensors are basically chip RTD elements pre-soldered onto printed circuit boards (PCBs) originally designed for use in domestic calorimeters.  The PCB has a meandering, zigzag circuit path to help minimise heat loss from the RTD to improve temperature measurement accuracy.  These RTD PCB sensors are sometimes preferred to NTC versions, as their inherent long-term stability is extremely important when accurately measuring and apportioning consumer energy consumption in district heating systems.

CWW Ceramic Wire-Wound platinum RTD Elements from Sensor Technology Ltda. are characterised by their extremely high stability, high-temperature capability and high accuracy over a very wide temperature range.  Sensors can measure the temperature of gases, liquids and solids, from -196ºC to 850ºC, with a precision between 0.012Ω and 0.12Ω at 0ºC or between 0.03°C and 0.3°C at 0°C.

The ceramic RTD construction design consists of a platinum wire coil (or for Duplex versions, two coils) encapsulated in a very high purity, aluminium oxide ceramic tube.  The empty spaces remaining between the platinum coil and the internal tube walls are filled with a material which allow the platinum contraction and expansion movement during temperature variations.

CWW RTD elements have multiple applications, such as laboratory, process technology and high value-added equipment. Applications where a highly accurate measurement is necessary should be built with this sensor type and 4 extension wires, however 3-wire construction is the most commonly found.

ATC Semitec stock a wide range of thermostats from several world leading, innovative manufacturers. Whether your application is sensing air temperature in the central heating or air conditioning market sector, or surface temperature sensing on heating elements in home appliances, we will have a product which to suit your needs.

Our leading brands include PEPI (Portage Electric Products Inc), Asahi, Matsuo and Campini who form a comprehensive range of thermostats each offering specific benefits.

PEPI thermostats provide accurate temperature control and thermal protection from 5°C to 200°C. With calibration tolerances of ±3K and temperature differentials as small as 10K (or even smaller in creep-action designs) a PEPI thermal switch offers the best control to cost ratio available.  Typical applications include rechargeable batteries, small appliances and electric heater control.

ATC Semitec stocks a comprehensive disc thermostat range from leading manufacturers Asahi Keiki and EAW.

Snap-action 1/2″disc bi-metal thermostats (or button thermostats) provide very reliable, cost-effective temperature control and thermal protection for domestic appliances and electronic circuits with a choice of manual or automatic reset available. These thermal switches can be supplied with tight tolerances and narrow differentials to make very effective thermostats; or they can be calibrated with wide differentials to provide over-temperature protection as either a thermal cut-out or a thermal limiter.

ATC Semitec stock Campini air and surface-sensing adjustable thermostats which are widely used throughout the heating and domestic appliance industry.  A Campini thermostat’s large bimetal blade ensures excellent repeatability and minimum differential (hysteresis), thus ensuring reliable and accurate temperature control.

There are air-sensing thermostats (TY53) where the I²R effects of through current are negligible and also anticipatory designs (TY35-P) where current flowing through the bimetal blade helps trick the thermostat into switching “early”, thus improving the temperature control function.

These adjustable thermostats are capable of switching over 100k cycles with a current rating of 16A/250VAC, so loads of up to 4kW can be readily controlled.  With an angular spindle rotation of 300 degrees, you can accurately set the temperature to the desired control level from 6°C to 70°C.  Differentials between 1K~3K can be achieved and versions with anticipatory resistors can improve this further.  These variable thermostats can also be set down at their minimum setting (6°C±4K) to act as frost protection or anti-condensation controls.

PEPI (Portage Electric Products Inc) thermostats from ATC Semitec provide accurate temperature control and thermal protection from 5°C to 200°C.  With calibration tolerances of ±3K and temperature differentials as small as 10K (or even smaller in creep-action designs) a PEPI thermal switch offers the best control to cost ratio available.

PEPI C thermostats have creep-action contacts which can give very close control up to 200°C.  PEPI J(A) thermostats are the ultimate low-profile controls offering accurate snap-action control upto 160°C and 4A/250VAC.  PEPI model N and V thermostats are synonymous with rechargeable battery temperature control and are the smallest controls of their kind.

All PEPI thermostats carry a range of international safety approvals (e.g. VDE, UL, CSA) to the latest EN and IEC standards.

Matsuo thermostats are superior twin bimetal, electro-mechanical temperature controls offering precision thermal control.  These precision bimetal thermostats have a unique internal structure that offers a combination of tolerance, differential and repeatability that is un-paralleled in the industry.  The twin bimetal system minimises calibration drift and ensures a long contact life from 100,000 cycles to 1 million cycles depending on the applied load.

Matsuo thermostats offer excellent thermal protection and are ideal as anti-condensation thermostats, anti-freeze controls or frost protection thermostats.  Especially useful in remote location applications which demand long-term stability and maximum service life.

Matsuo thermostats are precision calibrated and then sealed within a PBT plastic housing giving excellent environmental resistance.  Calibrations from -10°C to +110°C are available with setting tolerances down to ±1.5K and differentials (hystereses) down to 3K.  AC loads up to 3A(250V) or 5A(125V) and DC loads up to 1.3A/24V or 0.8A/48V can be switched.

ATC Semitec stocks an extensive range of auto-reset, manual reset and self-hold thermal protection devices from some of the world’s leading manufacturers such as PEPI, ASAHI, SEFUSE, EAW and SEKI.

Thermal protectors are used as safety mechanisms which will protect your products from overheating in the result of an abnormal operating condition.  The thermal cut-outs will protect against an over-temperature situation which could ultimately help to prevent fires or major damage to electrical components or appliances.

ATC Semitec stock a range of snap-action 1/2″ disc-style thermostats from ASAHI which provide very reliable, thermal protection for domestic appliances and electronic circuits.

The typical application of a thermal cut-out is to keep a safe temperature below a particular threshold during abnormal operating conditions.  Also known as a thermal limiter or thermal switch, they normally open at high temperatures during a fault condition and then reset when the product temperature falls to a safe, predefined level.

PEPI (Portage Electric Products Inc) thermal cutouts provide over-temperature control and thermal protection from 5°C to 200°C. PEPI protectors can be calibrated down to a ±5K tolerance and with a wide temperature differential, they offer a compact solution to solve over-temperature problems.  The latest PEPI FCP and PEPI ST01 thermal protectors offer combined thermal/current overload protection and can readily switch up to 8A/250VAC or 12A/24VDC.

One of PEPI’s neatest designs is an integral “self-hold” thermal and current sensitive cut-out, the model JS. The PEPI JS protector latches open after tripping and is then reset remotely, thus offering the same benefit as fitting a manual-reset cut-out but without the disadvantage of having to access it.

ATC Semitec can help you with the design-in and supply of circuit protection components providing you with optimum circuit safety against a wide range of current, voltage and thermal overload conditions. Whatever your requirement we can advise you which of the following products within our Circuit Protection range would best fit your needs.

Our range of current limiting diodes or CRDs from Semitec are a very simple way of providing constant current circuits for LED control and protection over a wide voltage range (1V to 100V). By combining them in parallel or in series with a zener diode, even higher current and voltage ratings can be achieved.

ATC Semitec offer a wide range of Inrush Current Limiters from Thinking TKS with diameters from 5mm to 30mm. These are designed to protect front-end mains voltage supplies against current spikes at switch-on, giving protection against the blowing of fuses or tripping of circuit breakers and the damaging of components.

PEPI thermal protectors from ATC Semitec offer superior and reliable over-temperature protection from 5°C to 200°C with current ratings up to 15A/250VAC.  Their neat design small package sizes help to protect circuits in the tightest of spaces.

PEPI bi-metal protectors can be supplied as automatic-reset limiters, self-hold cut-outs or even one-shot fuses offering different levels of safety depending on what the application or approval standard requires.  PEPI C and V thermostats are auto-resetting whereas the low-profile PEPI JS offers self-hold, non-resetting protection for both 240VAC and 120VAC.

PEPI J-2 and PEPI H bimetal fuses offer the ultimate in reliable thermal protection, with some ceramic versions offering over-temperature protection up to 280°C.