Flow Sensors

The Innovative Sensor Technology IST AG thin-film mass flow sensors offer solutions for a wide variety of flow applications. The thin-film and membrane technologies incorporate highly accurate temperature sensors and heaters as core elements on the sensors. The flow sensors are applicable in gas (operating temperature range of -20 °C to +400 °C) and liquid (operating temperature range of -50 °C to +180 °C) and can measure flow rates and direction from 0 m/s to 100 m/s.

IST AG develops and manufactures thermal flow sensors and offers three different solutions for measuring flow rates in gas and liquid applications. The standard solutions are optimal for various flow applications but can be fitted to meet customer-specific requirements. For standard flow sensors, electronics for the evaluation are offered.

With many years of experience, IST AG also offers development of customer-specific applications in terms of sensor technology development and consultation. As part of the standard development process, IST AG offers support at the point of implementation - this way we ensure the best sensor solution for specific applications. 

Sensors for gas flow

The IST AG thermal mass flow sensor combines the benefits of small dimensions with a robust design and easy adaptation in various applications and housings. IST AG offers considerable solutions for various flow applications and the option to customize parameters to meet application-specific requirements at a beneficial pricing. The IST AG gas flow portfolio consists of thermal flow sensors based on both anemometric and calorimetric principles.

Development channels guarantee the best possible adaptation of the sensors, whether in terms of dynamic range, response time, directional detection or ambient conditions.

Contact us today with your individual flow sensor requirements!

  • FS - Flow Sensors

    Our FS7 is a standard solution ideally suited for various gas flow applications. The FS7.4W is specially designed for applications with temperatures up to 400 °C. Both of the thermal gas flow sensor series works on the anemometric principle and consists of two platinum resistors on one chip which is immersed in a flow channel - a small resistance which is used as heater and a high resistance which is used for the measuring of the gas temperature. The anemometric principle is based on a function of the flow speed and utilizes heat transfer principles to determine the flow velocity. The heater is set to a constant temperature difference above the ambient temperature detected by the temperature sensor. The FS2 works on the calorimetric principle and offers the possibility to detect flow speed and flow direction. 

    As flow passes across the heater, heat is carried from the heater to the medium, and energy is transferred into the fluid and the temperature difference decreases. Consequently the power on the heater has to be increased to reset the “original” temperature difference. As flow increases, so does the amount of heat that is transferred. The power needed to adjust the temperature difference is therefore a measure of the flow passing the sensor. By knowing the heat transfer, the flow rate can be determined from the amount of voltage compensation needed to maintain a constant temperature differential.

    The heater and the temperature sensor are made of platinum and feature excellent long-term stability. 

    The FS2 thermal gas flow sensor works on the calorimetric principle and consists of four platinum thin-film resistors - one platinum thin-film resistor used as heater, two platinum thin-film resistors used to detect the flow speed and flow direction and a temperature sensor for ambient temperature measurement. The heater is surrounded by two temperature sensors. As flow passes across the sensor, heat is carried from the sensor to the medium. As flow increases, so does the amount of heat that is transferred. This leads in an output signal which is a function of flow rate and direction. By knowing the heat transfer, the flow rate can be determined from the amount of voltage compensation needed to maintain a constant temperature differential. In no flow condition, these two resistors are heated up equally. If flow appears, one of them is cooled more than the other, depending on flow direction.

  • FS7 - Optimal for applications requiring a high sensitivity up to +150 °C

    The IST AG FS7 thermal mass flow sensors are the successors of the FS5 flow sensors and exhibit a symmetrical heater design and enhanced sensitivity. The FS7 flow sensor is applicable in gas and offer excellent long-term stability. The small thermal mass of the FS7 sensor provides a fast response time. Additionally, the standard FS7 sensor is also available with a housing which is easily implemented into various applications.

    Further advantages of the FS7 thermal mass flow sensor include:

    • Easy adaptation in various applications and housings
    • Excellent long-term stability
    • Simple signal processing
    • Simple calibration
    • Stable platinum technology
    • Excellent reproducibility
    • Customer-specific sensor available upon request.

    The IST AG FS7 flow sensors are optimal for measuring gas flow in various flow applications.

    For more information see:

    Data Sheet Flow FS7

    Application Note Flow FS7

    Furthermore, IST AG offers flow modules for the evaluation of the FS thermal gas flow sensor:

    Flow Demo Board - Optimal for evaluation of the FS

    The IST AG Flow Demo Board offers an easy evaluation of the FS thermal gas flow sensor. The Demo Board can be used as a Plug & Play tool and delivers a fast measurement result without any additional adjustments.

    Further advantages of the Flow Demo Board include:

    • Easy to use Plug & Play module with analogue output (not calibrated)
    • No microprocessor or software influenced signal
    • Simple CTA (constant temperature anemometer)
    • Simple gain adjustment

    For more information see:

    Data Sheet Flow Demo Board

    Quick Start Guide Flow Demo Board

  • FS7.4W - Optimal for applications requiring a high sensitivity up to +400 °C

    The IST AG FS7.4W gas flow sensor has been developed for applications with temperatures up to 400 °C. The design of the FS7.4W is based on the FS7 design which offers a symmetrical heater that enhances sensitivity. The FS7.4W flow sensor is applicable in gas and offers excellent long-term stability. The small thermal mass of the FS7.4W sensor provides a fast response time.

    Further advantages of the FS7.4W thermal mass flow sensor include:

    • Easy adaptation in various applications and housings
    • Excellent long-term stability
    • Simple signal processing
    • Simple calibration
    • Stable platinum technology
    • Excellent reproducibility
    • Customer-specific sensor available upon request

    The IST AG FS7.4W flow sensors are optimal for measuring gas flow in various flow applications.

    For more information see:

    Data Sheet Flow FS7.4W

    Application Note Flow FS7

    Furthermore, IST AG offers flow modules for the evaluation of the FS thermal gas flow sensor:

    Flow Demo Board - Optimal for evaluation of the FS

    The IST AG Flow Demo Board offers an easy evaluation of the FS thermal gas flow sensor. The Demo Board can be used as a Plug & Play tool and delivers a fast measurement result without any additional adjustments.

    Further advantages of the Flow Demo Board include:

    • Easy to use Plug & Play module (not calibrated)
    • No microprocessor or software influenced signal
    • Simple CTA (constant temperature anemometer)
    • Simple gain adjustment

    For more information see:

    Data Sheet Flow Demo Board

    Quick Start Guide Flow Demo Board

     

  • FS2 - Optimal for measuring gas flow and direction

    The IST AG FS2 flow sensors are applicable in gas and offer excellent long-term stability. In addition to measuring flow rates, the FS2 gas flow sensor is able to detect flow direction with outstanding sensitivity.

    Further advantages of the FS2 thermal mass flow sensor include:

    • Simple signal processing
    • Simple calibration
    • Bare sensor resists up to +450 °C (customer specific)
    • Stable platinum technology
    • Excellent reproducibility
    • No moving mechanical parts
    • Customer-specific sensor available upon request

    The IST AG FS2 flow sensors are optimal for measuring gas flow and direction.

    For more information see:

    Data Sheet Flow FS2

  • SFS - Silicon Flow Sensor

    The SFS is IST AG's first flow sensor based on silicon technology. It is operated according to the calorimetric principle and can therefore detect not only the flow velocity but also the flow direction.

    The symmetrical design of the SFS flow sensor allows an easy interpretation and evaluation of the measurement signal. The sensor can be used in different gases. It is characterized by a high sensitivity, a very fast response time and an extremely low energy consumption.

    IST AG offers the full range of cooperation, from support with the customer's system integration to pre-assembled, customer-specific partial solutions and a complete solution tailored to the customer's application.

  • SFS01 - For the ultra-fast measurement of low flow rates

    The SFS01 is particularly suitable for low flow velocities up to 3.5 m/s (in gases). It shows very fast measurement results of the flow rate as well as the flow direction.

    The Silicon Flow Sensor SFS01 offers three main characteristics:

    • Very fast response time <5 ms
    • Very low energy consumption
    • Easy system integration including temperature compensation

    Well-adapted channel geometries allow the performance of the sensor to be optimally aligned to the desired application. The SFS01 flow sensor is ideally suited for space-limited applications, but can also be easily upgraded to complete ready-to-use systems.

    Suitable application areas for the SFS01 flow sensor are flow measurements in battery-operated / portable devices, air conditioning technology (HVAC), automation technology as well as process and control engineering.

    For more information see:

    Data Sheet SFS01

    Application Note SFS

    SFS01 EvaKit - Optimal for easy evaluation of the Silicon Flow Sensor

    The IST AG SFS01 EvaKit offers an easy evaluation of the SFS01 gas flow sensor. It has both analog and digital output (I2C) and allows a fast and flexible evaluation of the SFS01 sensor. The I2C output includes both raw values and calibrated flow values from 0 to +- 200 sccm.

    Further advantages of the SFS01 EvaKit include:

    • Excellent measuring dynamics
    • Analog output of raw signal
    • Digital output with raw signal and fully calibrated signal
    • Integrated flow channel with pneumatic connections

    For more information see:

    Data Sheet SFS01 EvaKit

  • MFS - MicroFlow Sensors

    The MFS thermal flow sensor can be used in a wide flow range from 0 to 150 m/s (CTA mode) and in a temperature range from -40 °C to +80 °C. It is used for flow measurement of a wide variety of gases. A special feature of the MFS sensor is that it is also suitable for industrial flow applications with smoke or exhaust gas development. The MFS sensor can be operated in either anemometric or calorimetric mode. It is also suitable for measuring the flow direction.

    MFS flow sensors are based on a photosensitive glass substrate with a thin polymer layer that serves as a membrane.

    IST AG offers you customer-specific adaptations of the MFS sensor - from adaptations based on chip level to joint developments of an individual overall solution. In this way we ensure that the sensor is optimally adapted to your application.

  • MicroFlow - High performance over a wide dynamic range

    The IST AG MicroFlowSens (MFS) technology was developed for fast flow measurements. Due to the membrane system, the thermal mass is reduced to the minimum resulting in a very fast response time and low power consumption. In addition to measuring flow rates, the MicroFlowSens offers an outstanding sensitivity and is able to detect flow direction. The MFS flow sensor is optimal for limited space system integration and is available as integrated sensor on a PCB.

    Further advantages of the MFS thermal mass flow sensor include:

    • Excellent solution for applications with high flow rates and fast response time in CTA mode
    • Very high measuring dynamic with CTA mode (10'000'000 : 1) without bypass
    • Excellent for the measurement of very low flow rates and leakage detection with bridge mode
    • High chemical resistance against aggressive gases and vapors
    • Different sensitivities and circuit topologies available
    • Detection of flow direction
    • Customer-specific sensor layout upon request

    The IST AG MFS gas flow sensor is optimal for measurements in process control, hand held devices and in medical applications.

    For more information see:

    Data Sheet Flow MFS02

    Different designs of the MFS offer the possibility to match the sensor that is best suited for the requirements of the application.

    The table below indicates a comparison of the most significant sensor parameters.

    Furthermore, IST AG offers flow modules for the evaluation of the MFS thermal gas flow sensor:

    MicroFlow Amplifier Module - Optimal for demonstration and evaluation of the MicroFlowSens

    IST AG MicroFlow Amplifier Modules offer an easy evaluation of the MicroFlowSens gas flow sensor. The MicroFlow Amplifier Module can be used as a Plug & Play tool and delivers a fast measurement result without additional adjustments. In this module, the MFS02 sensor is connected in the bridge configuration. The non-calibrated bridge voltage is a function of the flow speed and direction.

    Further advantages of the MicroFlow Amplifier Module include:

    • Single supply 12 VDC
    • Flow channel and pneumatic connectors mounted
    • Separate temperature sensor on chip
    • Monitoring for internal supply, offset and heater voltages at termination block
    • Interfacing with screw termination block
    • Adjustment with three trimming potentiometers (gain, offset and heater voltage)

    For more information see:

    Data Sheet Flow MFS Amplifier Module

    MFM.EVAL.01.DI2C - Optimal for very low differential pressure applications

    The IST AG MFM.EVAL.01.DI2C flow module offers a differential pressure measurement of up to 5 Pa fullscale, evaluation with the supplied software and an I2C- or SPI-to-USB converter. In addition to the integrated measurement of temperature, the dynamic differential pressure module offers a patented flow measurement, two million digital counts with a 5 mPa noise free resolution and repeatability near zero with less than 0.02 % full-scale. 

    Further advantages of the MFM.EVAL.01.DI2C include:

    • MFS05 MicroFlow sensor - MEMS component
    • 24 bit resolution (flow / pressure)
    • 5 Pa operating measuring range
    • Patented flow measurement
    • Integrated temperature measurement with 24 bit resolution
    • Digital (I2C, SPI) or PWM signal output

    For more information see:

    Data Sheet Flow Differential Pressure Module

  • MIDAS M1.x (prototypes available) - Optimal for easy integration and ultra-fast measuring of gas flow and direction

    The IST AG MIDAS M1.x gas flow sensor offers the advantages of the MicroFlowSens technology supplied in MID housing with integrated flow channel and solderable contact pads which can be soldered directly to a PC board. The MID housing is additionally developed with a built-in flow channel, which provides simple system integration. The MIDAS M1.x is available with three different flow channel geometries and a customer-specific sensor and flow channels upon request. Due to the special design of both sensor and flow channel, the output signal of this system features an extreme low temperature dependency (<2% of full scale without external temperature compensation).

    Further advantages of the MIDAS M1.x include:

    • Detection of flow direction
    • Ultra-fast response time
    • Excellent for low mass flow
    • Low power consumption
    • Suitable for automated pick-and-place PCB assembly
    • Small thermal mass
    • Excellent symmetry - low offset
    • Low temperature dependence also under non-isothermal conditions
    • Excellent long-term stability

    The IST AG MIDAS M1.x is optimal for easy integration and ultra-fast measuring of gas flow rate and direction.
    Prototypes of the MIDAS M1.x are available, regular production will start soon. 

    For more information see:

    Data Sheet Flow MID

Sensors for liquid flow

The Innovative Sensor Technology IST AG thermal mass flow liquid sensors combine the benefits of small dimensions with a robust design and easy adaptation in various applications and housings. IST AG offers the possibility to customize various parameters to meet application-specific requirements cost-effectively.

Contact us today with your individual flow sensor requirements!

  • Out of Liquid - Optimal for flow applications in aggresive liquids

    The IST AG Out of Liquid flow sensor utilizes the reliable and proven thermal mass flow measuring principle and is specially developed for flow applications with aggressive liquid media. The sensor provides the flexibility of easy adaption in an application and at a lower cost. Measuring flow directly in a liquid channel has proven a difficult task without dramatically shortening the lifetime and damaging the sensor. The Out of Liquid flow sensor offers the possibility to create no-flow / flow switches. It also offers the possibility of an extremely accurate measurement. A heater and a temperature sensor chip, both with backside metallization, are soldered on the stainless steel flow channel providing an excellent thermal contact with the liquid without being in direct contact with it, meaning even aggressive liquids can be measured easily with this sensor.

    Further advantages of the Out of Liquid flow sensor include:

    • High chemical resistance
    • No contact between sensor and liquid
    • Simple flow switches possible

    The IST AG Out of Liquid flow sensors are optimal for measuring liquid flow in aggressive liquids.

    For more information see:

    Data Sheet Flow Out of Liquid

    Furthermore, IST AG offers flow modules for the evaluation of the Out of Liquid flow sensor:

    Out of Liquid Demo Board - Optimal for demonstration of flow applications in aggressive liquids

    The IST AG Out of Liquid Demo Board has been developed for demonstration of the Out of Liquid flow sensor. The Out of Liquid Demo Board can be used as a Plug & Play tool and delivers a fast measurement result.

    Further advantages of the Out of Liquid Demo Board include:

    • Single supply 5 VDC
    • No contact between sensor and liquid
    • Suitable for aggressive liquids
    • Adjustable by the customer

    For more information see:

    Data Sheet Flow Demo Board

    Quick Start Guide Flow Demo Board