Frequently asked questions about iST, our portfolio and services
Customer support
Call us, visit us or fill in the contact form below.
You will find all contact details of all our facilities under "Contact"
You can order sensors from our headquarters in Switzerland, iST Shanghai or iST USA. We have a number of distributors across all contintents. Go the the distributors page to find the one closest to you!
Use plastic tweezers for handling. Lead wires should not be bent or twisted close to the element to avoid over-straining of the leads. Consult our app note for correct sensor handling. You will find clear and visual instructions.
Depending on the wire composition, the sensor can be connected by:
- Crimping
- Soft soldering
- Brazing
- Welding
About the iST Group
The iST Group has around 450 employees worldwide. Production facilities are located in Ebnat-Kappel, Switzerland and Roznov, Czech Republic. Our sales offices offer engineering support and sales in Las Vegas, USA, Mumbai and Calcutta, India, as well as in Shanghai, China.
Our subsidiaries are:
Senstech AG, Fehraltorf, Switzerland, www.ist-senstech.com develops and manufactures Force Sensors
Jobst Technologies, Freiburg, Germany, www.ist-jobst.com develops and manufactures Biosensors
Infrasolid, Dresden, Germany, www.infrasolid.com develops and manufactures Thermal Infrared Emitters
IST Innuscreen, Bernlin, Germany, www.ist-innuscreen.com develops and manufactures DNA & RNA Extraction Kits
Go to the Download Section on the website. You can use the Filter on the left hand side to sort measurable parameters.
iST was founded in 1991 and has been growing steadily ever since. Go to our history page to learn more about our success story.
Yes, iST and all our subsidiaries hold ISO 9001_14001 certificates. They are availabele for download in the Download Section of our website. You can narrow down the search by using the "Certificates" filter under "Other Documents" https://www.ist-ag.com/en/download on the left hand side.
We are always on the lookout for new talent! If you go to the "Join us" section of our website you will learn all about how to apply for a job at iST.
The job openings are listed here
Our management team is introduced in the "About us" Section here.
iST is a company of the Endress+Hauser Group, headquartered in Reinach, Switzerland. Endress+Hauser is among the global leaders in measuring instruments, services and solutions for industrial process engineering. www.endress.com
Our sensors are primarily manufactured at our headquarters in Ebnat-Kappel, Switzerland. This production facility specializes in the development and production of thin- and thick-film platinum and nickel RTD temperature sensors, micro-heaters, capacitive humidity sensors, thermal mass flow sensors, conductivity sensors and gas sensors.
Additionally, we operate a production site in Rožnov pod Radhoštěm, Czech Republic, which enhances their manufacturing capacity, flexibility, and efficiency. This site employs around 200 people and supports the Swiss headquarters in meeting global demand.
Our biosensors are developed and manufactured by our daughter company iST Jobst in Freiburg, Germany while our other daughter company iST Sensech specializes in Force sensors, wich are produced in Fehraltorf, Switzerland.
Infrasolid is another daughter company in Germany. They are specialized in the development and manufacturing of Infrared Emitters and are located in Dresden.
There are many steps involved, from the conception with choice of design to the actual production process, which starts with the deposition of platinum layer on ceramic substrate. Various cleaning processes follow, then photolitography, etching, laser trimming, screen printing, dicing, welding and measuring. There are several in-process inspections as well as final inspections. The full production process is described here.
Yes, you can. There is a selection of our most popular sensors available in our webshop.The sensors listed there are ideal for design-in, testing and developing, you can buy small sample-quantities from our webshop. The sensor-finder will help you narrow down your search. Should you not find what you need, our sales team will be happy to help. Just click on the "Request sensor" link, and you can define your sensor criteria in the sensor request form.
If you are interested in small order quantities larger than what the Webshop has in stock please select the "Request quote" link.
Our webshop is designed for small order quantities. There is a selection of our most popular standard sensors available in our webshop. For larger order numbers we recommend you contact us. If you can't find what you need in our shop please contact our sales team who are happy to advise you on the sensor best suited for your application.
About our sensors and services
As a general rule:
- Do not touch the sensors without wearing rubber gloves
- Do not use metal tweezers but always plastic tweezers
- Grip the sensors by the contacts, not the "body"
- Always study application note before handling the sensors, where you will find photos and clear instructions on the correct handling of our sensors
- All Application Notes are available for Download in here. Use the filter on the left to select the measuring parameter.
Yes, customization is one of our major strengths! Choosing the right materials and technologies for your application are key to the future success of your product. At the first meeting with our engineers and the customer specific application requirements are discussed. Depending on the complexity of the project the solution can either be an existing sensor, an existing sensor with minor adjustments or a custom made design. For custom designs, prototypes are developed and thoroughly tested. More on our customization options here.
- 100% Electrical test acc. IEC60751 for nominal resistance and TCR value
- 100% visual inspection
All application notes are available in the Download section of this website. The Application note for Platinum RTDs can be accessed here.
Portfolio
Temperature sensors
The wires of a platinum resistance temperature sensor are used to connect the sensor to a measurement or control device (like a temperature transmitter, PLC, or data logger). They are used for temperature monitoring in just about anything, e.g. machines, pipes, tanks, are embedded in equipment like ovens, autoclaves, and HVAC systems, medical equipment, connected to controllers for automated temperature regulation or integrated into into data acquisition systems for logging and analysis
Pt 100 SMDs are ideal for applications that demand compact dimensions, compatibility with automated PCB assembly, and cost-efficiency. Typical use cases include consumer electronics, automotive systems, medical devices, industrial automation, energy solutions, and HVAC systems.
Yes, our latest generation of platinum temperature sensors achieves the excellent test results and makes them ideal for fuel cell technology and EV-applications.
Thanks to their optimized design and new process technology, our platinum RTDs are characterized by excellent ESD resistance. The designs have been tested according to the European Union standards, IEC/EN61000-4-2.
For example, iST's Pt 100, size 232, exceeded Level 4 with a maximum drift-free voltage of 10 kV
iST's EDS-optimized sensors have been tested acc. IEC 61000-4-2 and meet or exceed the requirements. Choosing a temperature sensor component with ESD (Electrostatic Discharge) optimized design is important for several reasons, especially in environments where reliability, longevity, and safety are critical:
Maximize yield:
ESD events can occur during handling, assembly, or operation, and may permanently damage sensitive electronics. An ESD-optimized sensor includes built-in protection circuitry that absorbs or redirects electrostatic energy, preventing internal damage and expensive maintenance and downtime
Long-term stability:
ESD damage might not always cause immediate failure—it can lead to latent defects that degrade performance over time. With an ESD-optimized design, the temperature sensor is more robust and reliable, reducing the risk of intermittent faults or early failure.
Suitable for industrial and harsh evironments:
In industrial settings, ESD events are more common due to machinery, dry air or human interaction. ESD-optimized sensors are designed to withstand these conditions, making them ideal for EVs, factory automation, HVAC systems, and automotive applications.
Electrical resistance of platinum (Pt) changes predictably with temperature. A Pt 100 works on this principle.
A Pt100 is a type of resistance temperature detector (RTD) used to measure temperature. The "PT" stands for platinum, and the "100" indicates that it has a resistance of 100 ohms (Ω) at 0°C.
A wire-wound Pt100 is a type of platinum resistance temperature detector (RTD) where the sensing element is made by winding a thin platinum wire around a ceramic or glass core. This design is one of the most traditional forms of Pt100 sensors.
As a standard, iST offers the following resistances:
50 Ω, 100 Ω, 200 Ω, 500 Ω and 1000 Ω All others are on request
For our customers, we have produced various other resistances.
The structure of a Pt 100 sensor in SMD (Surface-Mounted Device) design is specifically engineered for compact, automated placement on printed circuit boards (PCBs). iST SMDs are taped on reel to enable fast and automated assembly.
iST RTDs are used in temperature ranges from -200 °C to + 1000 °C
iST offers a wide range of sensors based on different technologies suitable for any application.
Our platinum RTD sensors are extremely robust, highly accurate operate with low drift.
Our nickel sensor components offer excellent long-term stability and are easily replaceable.
Our TSic solid-state temperature sensors are calibrated with an integrated signal converter for analog or digital output - accurate, reliable and easy to integrate.
Learn more about the different sensor types here
- Miniaturized: Thin-film RTDs are built by depositing a platinum layer on a ceramic substrate, making them very compact ans small in size. This allows for better integration in tight spaces where wire-wound sensors would be too bulky. Their small form factor are ideal for compact equipment requiring miniaturized design.
- Low Thermal Mass: Because of their thin construction and low thermal mass, thin-film sensors have less material to heat up or cool down, which results in faster thermal equilibrium when the process temperature changes and improved control accuracy in dynamic systems
- Thermal shock and vibration resistant: Thin-film elements are mechanically robust and withstand vibration and mechanical stress better than delicate wire-wound coils. They handle rapid temperature changes without cracking or breaking, making them suitable for harsh industrial environments.
- Fast responce time: The combination of small size and low thermal mass allows for a fast reaction to temperature changes, which is critical in processes where timing matters (e.g., automotive, aerospace, or high-speed manufacturing).
- Economy: Thin-film RTDs have a better price/performance ratio because they are less expensive to produce than precision wire-wound sensors and offer excellent accuracy and stability for most industrial applications, making them a cost-effective choice unless ultra-high precision is required
The wire-wound construction typically requires more space, making it less suitable for compact or embedded applications. Their production cost is higher, especially for Pt1000 and compared to thin-film RTDs, they have a slower response time.
Space Sensors
iST Space sensors are HiRel temperature sensors. They are ESCC qualified and are available as flight model (FM) or engineering models (EM). The RTD’s are available with different resistances ranging from Pt100 to Pt2000. They can be used in a temperature range from -200 °C to +200 °C and are classified as tolerance class B (IEC 60751 F0.3
iST's temperatures sensors are specifically designed for Space applications and were subject to stringent testing and certification. This means the have been subjected to long-term rigorous tests required by ESA to withstand harsh space conditions, thermal stress and vibration.
Qualified Flight Model (FM)
Engineering Model (EM)
The sensors are available as flight models or engineering models with a resistance of 100 Ω, 200 Ω, 500 Ω, 1000 Ω or 2000 Ω within temperature ranges of -50 °C to +150 °C or -200 °C to +200 °C with platinum leads only
- With twisted 2-core extension wires
- With twisted 4-core extension cables
- With or without shield and jacket ith extension
- Cables available from 100 mm up to several meters
Yes. See Detail specification reference No. 4006/015
On the iST website under the "Space" Page or directly under the download:ESA_Certificate_of_Qualification_352C.pdf or directly at ESA under RESISTANCE TEMPERATURE DETECTOR THIN FILM PLATINUM SENSOR, PTC, RANGE 100 TO 2000 OHMS AT 0°C, WITH A TEMPERATURE RANGE OF -200°C TO +200°C
Space Sensors
For more information on iST's Space sensor portfolio visit the Space section of our website.
Flow Sensors and modules
Different sensors for different applications are available for gas as well as liquid flow measurement
20 sccm- 250000 sccm
Please go the webshop for comparison of our flow sensors or have a look to the datasheet in the Download section of our website.
SFS01: ~ 10 ms
MFS02: < 10 ms
SF2: < 500 ms
FS5: ~160 ms
FS7:~200
Flow Switch Module: < 3 s
SFS modules: 20 ms
OOL sensor: 300-500 ms
OOL mass flow meter: ~500 ms
OOL bubble detector: 6 ms
Humidity Sensors
iST humidity sensor elements are capacitive elements without electronics. They require capacitive measurement and calibration to determine humidity.
iST humidity modules come with basic electronics and calibrationand provide measurement values in °C and %rH) via an I2C interface.
Yes! iST offers customized solutions for assembly and calibration, tailored to your specific requirements.
The active area of humidity sensor elements is very sensitive and easily damaged. Please avoid any contact with the active area or contamination with glue, flux, solder, particles etc. Always handle them with plastic tweezers, as metal ones can scratch the active area. Do not touch the sensor with your bare fingers and always wear rubber gloves when removing them from their packaging.
The active sensor area and electronics of the HYT 271 are not protected by a cap, due to the module’s small size and needs the same care when handling as the sensor elements.
For the humidity modules HYT 221, 223, 939 make sure the filter doesn’t get blocked, as the air exchange and humidity transfer to the element will no longer work.
Please also avoid any local pressure on the glob top, as this might lead to damage in the electronics beneath.
Detailed handling instructions can be found in the application notes.
iST humidity sensors have excellent linearity and low hysteresis. They provide accurate readings with minimal deviation.
The standard calibration for our modules is +/- 1.8 % RH but can be customized to reach even higher accuracies.
iST humidity sensors boast a wide measuring range from 0 % RH to 100 % RH
iST sensors and modules perform with excellent response times with t69 < 500ms like our P14 Rapid 2, or the heatable P14 4051FW Thermo Rapid 2. If you prefer a module we recommend the HYT.R511.
The operating temperature range of our humidity sensors elements depends on the element and can range from -80°C to +190°C. Our humdity modules have an operating temperature range from -40 °C to +125°C.
iST offers sensors and modules with fast response times which make them suitable for dynamic environments.
iST offers a growing portfolio of capacitive humidity sensor elements designed for accurate measurements for various environments:
- in low humidity ranges (K5)
- with ultra-fast response times (P14 Rapid 2)
- harsh environments (MK33)
- with an integrated heating element (P14 2FW Thermo) for measurements where fast recovery time is required.
For many of them different versions regarding dimensions and contacting options are available. The sensor finder on our front page will give you an idea of our portfolio and allows you to compare multiple sensors. You can also buy smaller quantities there.
Before using any humidity sensors, a sensor-specific calibration must be performed.
Our modules, on the other hand, come with a factory calibration, which means they can be used directly in your application without the need for any additional calibration.
If the sensors are exposed to VOCs, they can be recovered by baking for 6 hours at 120 °C or 12 hours at 80 °C. For additional information, refer to the application note under the section “Sensor Pollution.”
Measuring capacitance requires careful attention to detail, as various factors can significantly influence the accuracy of the readings. One critical aspect is the wiring connected to the sensor. While it is technically possible to extend the sensor with additional wires, we strongly recommend keeping the connection as short as possible.
Extended wires introduce an offset in the measurement and can degrade signal quality. Moreover, external noise and parasitic effects such as electromagnetic interference can further distort the readings. To mitigate these issues, we advise using shielded cables for all connections to ensure signal integrity and minimize interference
Thanks to the digital I2C interface, the sensor can be easily integrated into existing measurement and monitoring systems.
An evaluation kit for initial testing is available in our webshop
The evaluation kit contains:
A factory-calibrated HYT271 module for measuring humidity and temperature
A test board with digital (I2C) and analog (0–10 V) outputs
An easy-to-use probe assembly
A micro USB interface for connection to a PC
Compatibility with the Arduino IDE – ideal for developers and technicians
Yes, the kit is specially designed for application testing and allows you to quickly and easily evaluate the sensor in your environment.
Humidity sensors are essential components in many applications where precise humidity control is critical. While they are most commonly used in HVAC systems to regulate indoor air quality and comfort, they also play vital roles in industries such as agriculture, automotive, medical devices, dry rooms, and consumer electronics, ensuring optimal environmental conditions, protecting sensitive equipment, and enhancing user experience.
In the low humidity range our K5 sensor element is the best solution, since it offers a high resolution even in the low dewpoint range. Also available as fully calibrated modules with accuracies down to +/- 0.5%RH.
We are happy to discuss custimizations to match further requirements (e.g. heatable option).
Yes: In the low humidity range our K5 sensor element is the best solution, since it offers a high resolution even in the low dewpoint range. Also available as fully calibrated modules with accuracies down to +/- 0.5%RH.
We are happy to discuss custimizations to match further requirements (e.g. heatble option).
The HYT 939 with PTFE filter and the Heated HYT with PTFE Filter are both best suited for VOC contaminated environments. The Heated HYT offers an additional reconditioning by a customizable heating step right in the application.
Depending on the form factor, the HYT271 or HYT939 are the modules of choice. Ask for customized assembly options.
The HYT939p in TO39 packaging is very pressure-tight up to 16 bar. Its glass-to-metal seal makes it mechanically robust. The round stainless-steel cap can easily be fitted into housing openings, and it can easily be sealed against a wall with the use of an O-Ring.
The Heated HYT with PTFE Filter is best suited for VOC contaminated environments in food processing or industrial drying applications. The Heated HYT can be reconditioned by a customizable heating step in the application and does not need replacement.
For weather data aquisition, we recommend a fast responding humidity sensor with t69 < 500ms like our P14 Rapid 2, or the heatable P14 4051FW Thermo Rapid 2 to prevent icing during the flight. If you prefer a module we recommend the HYT.R511
For weather data aquisition, we recommend a fast responding humidity sensor with t69 < 500ms like our P14 Rapid 2, or the heatable P14 4051FW Thermo Rapid 2 to prevent icing during the flight. If you prefer a module we recommend the HYT.R511
Our MK33 elements are best suited for measurment in oil and other harsh conditions. They are available as elememts, as calibrated module in the HYT 271 dimension or in a robust and compact screw-in stainless steel housing with a metric M14 thread.
The sensor measures the relative humidity (%RH or water activity aw) and temperature in oils and fuels. These values provide information about the current oil quality and help to plan maintenance measures at an early stage.
Water activity shows how much water the oil can currently absorb – a direct indicator of the lubricant's performance. Measuring in ppm, on the other hand, only provides the absolute water content without taking the condition of the oil into account.
Typical areas of application are marine engines, commercial vehicles, wind turbines, generators, drilling and paper machines, and mobile oil filtration units.
Conductivity Sensors
iST offers conductivity elements from 1 uS/cm up to 200 mS/cm
Higher temperature leads to higher conductivity values
Planar geometry on a ceramic chip
According to IEC 60751:
-50 °C to 0 °C R(T) = R0 x (1 + A x T + B x T2 + C x (T100) x T3 )
0 °C to 150 °C R(T) = R0 x (1 + A x T + B x T2)
A = 3.9083 x 10-3 x °C-1
B = -5.775 x 10-7 x °C2
C = -4.183 x 10-12 x °C-4
R0 = resistance value in Ω at T = 0 °C
T = temperature in accordance with ITS90
Compared to traditional 2-electrode designs, a 4-electrode geometry has several advantages, especially in regard to stability, accuracy, resistivity and interferance.
- Ionic double layer effects can be removed from the measurement
- Elimination of polarization at the electrode-solution interface
- Higher accuracy, especially in low-conductivity solutions like ultrapure water
- Wider measurement range
- Enhanced signal stability
- Higher stability and lower degredation
Biosensors
Our biosensors are ready to measure up to four analytes in parallel continuously: glucose, lactate, glutamine and glutamate. Their micro-miniaturized form factor allows for very low sample consumption for such a multi-analyte read-out.
Our biosensors can measure directly in most cell culture media, whole blood, interstitial fluid, cerebreal fluid, perfusion media, sweat and more. The biosensors work best at neutral pH in PBS, Acetate, Bicarbonate and other buffer systems. They work in a temperature range of Temperatures of 0°C-40°C.
Our B.LV5 biosensor can monitor most bioreactor media in bioprocessing. They feature very low sample consumption and measure continuously in perfusion as well as bypass streams. The sensor can be connected by LUER lock or alternatively to 3/8’’, 1/4'', 1/2'' and 1'' tubing.
Our biosensor components are used by integration providers in dedicated at-line analyzer modules for automated hands-free operation as well as in in-line continuous monitoring PAT. Sterile barriers like semipermeable membranes, check valves, peristaltic pumps or filter probes can interface closed bioreactor systems to our sensor components. For in-line monitoring radiation sterilized biosensors can be mounted directly into perfusion lines and reactor chambers.
Our biosensors and proprietary glucose sensor technology provide long term glucose readout in various body fluids including ISF. Contact us for OEM services and capabilities.
Our biosensor components can be customized to host the dedicated analytical panel and interface with various flow cells in device construction. Our long lifetime in operation of over 2 months, dry storage capability and high linear range for glucose and lactate measurement enable highest performance and cost effective device design for blood gas analyzer.
Our biosensors provide longterm stable readouts in operation. Typical lifetimes at high analyte levels during continuous operation are
>60 days for glucose and
>7 days for lactate.
In intermittent sample operation the lifetime is considerably longer.
Our biosensor components are manufactured in a controlled environment with low bioburden. The biosensors are compatible with gamma- and beta-irradiation to lower CFU numbers even further to enable sterility of the final device.
Our off-the-shelf evaluation units are available in our webshop ready to order for testing and evaluation. We also provide USB-connectable 6-channel transmitter for plug-and-play operation and free to use GUI and data saving software. With our B.IV4 probe type sensors dip-in measurements in beaker volumes as low as 50 µl are possible while our B.LV5 comes in ruggedized construction and easy LUER-Lock fluid lines for flow-through measurements out of the box. Reach out to [email protected] for support and sourcing.
Micro-Heaters
A platinum heater track is applied on an alumina substrate and covered with glass to protect the heater. The heaters are contacted with wires. The type of wires used depends on the temperature in use.
Though iST has a few standard micro-heaters in the shop, the size and shape depends entirely on the application it is used in. We specialize in custom-built micro-heaters designed to target-heat small spaces
There are two control strategies, Feedforward or Feedback. Heater temperature can also be determined by the resistance in use
Yes, the resistance increases with increasing temperature. Higher resistance leads to more heat generation for a given current. Resistance depends on:
- Material type (e.g., platinum, polysilicon)
- Geometry (length, width, thickness of the meander structure) influences heat distribution
- Temperature (resistance can change with temperature)
In short: Applied voltage, conduction, convection and radiation .
The temperature is determined by both electrical and physical factors. It increases with the electrical power supplied, according to Joule's law, where:
- P is power,
- I is current,
- V is voltage,
- R is resistance
Material and structural properties also determine the temperature of iST micro-heaters. Environmental conditions, such as ambient temperature, airflow around the heater, conduction and radiation also influence the temperature of a micro-heater.
iST heaters can cope with up to 85 W
The selected materials should withstand the corresponding temperature (T > 300°C - kapton tape may work). The heaters are available with metallized backsides for soldering or sintering.
The range of applications are wide-ranging across many markets and industries. Here are a few examples:
- Medical devices and industrial or scientific instrumentation for temperature control in analytical insstruments or for controlled heating for diagnostics or therapy in drug delivery systems or tissue stimulation
- In Gas sensors for the detection of CO, NO2, CH4, or VOCs in environmental monitoring
- De-icing systems to help prevent moisture build up or ice formation in automotive mirrors or optical sensors
- In infrared sourcess for thermal imaging calibration or gas analysis
- In micro-valves, switches, or mechanical deformation in MEMS devices for thermal expansion to create movement
- In microfluidic & lab-on-a-chip systems to control chemical reactions
- Heating tabacco
Contact request
Our contact request form will put you in contact with the right specialist for your inquiry. Our customized sensor request form will help you specify your sensor request.