Sensortechnics’ LBA-Differenzdrucksensoren basieren auf der thermischen Massen-durchflussmessung von Gas durch einen sehr kleinen, im Sensor-Chip integrierten Strömungskanal. Die Sensoren eignen sich vor allem zur Durchflussbestimmung nach dem Wirkdruckverfahren, bei dem der Druckabfall über einem Strömungselement gemessen wird. Hochwertige Beatmungs- und Atemtherapiegeräte müssen kleinste Strömungen um den Nullpunkt des Atemflusses sicher erkennen und zusätzlich Durchflüsse von mehreren hundert l/min messen. Für diese besonders hohen Anforderungen bietet Sensortechnics nun spezielle Versionen seiner LBA-Drucksensoren mit Auflösungen von 0,01 % im unteren Druckbereich und gleichzeitig dynamischen Messbereichen größer 10.000.

Die LBA-Sensoren bieten einen neuartigen MEMS-Aufbau, bei dem der Strömungskanal und eine analoge CMOS-Signalaufbereitung auf einem winzigen Siliziumchip integriert sind. Der enge Kanal verringert die Strömung durch den Sensor um mehrere Größenordnungen im Vergleich zu herkömmlichen durchflussbasierten Drucksensoren. Die LBA-Differenzdrucksensoren sind daher sehr unempfindlich gegenüber Staub und Feuchtigkeit und erlauben den Einsatz von langen Verbindungsschläuchen und Filtern, ohne dass das Sensorausgangssignal beeinflusst wird. Außerdem entfallen aufwendige Gehäusekonstruktionen, wodurch die LBA-Sensoren sehr klein und kostengünstig gebaut sind und einfach auf Leiterplatten montiert werden können.

Die wichtigsten Merkmale der LBA-Differenzdrucksensoren:

- 0,01 % Auflösung und dynamischer Messbereich größer 10.000

- Sehr unempfindlich gegenüber Staub und Feuchtigkeit

- Kein Einfluss von Verbindungsschläuchen und Filtern auf das Sensorsignal

- Miniaturgehäuse zur Leiterplattenmontage

Sensortechnics’ LBA-Sensoren mit 0,01 % Auflösung eignen sich hervorragend zur Differenzdruckmessung in Beatmungsgeräten, Spirometern sowie Schlafdiagnose- und Atemtherapiegeräten.

New Stainless Steel OEM Pressure Sensors Offer High Accuracy

Sensortechnics' new SSI stainless steel OEM pressure sensors accurately measure gage or absolute pressures in ranges from 200 mbar up to 35 bar. These devices offer excellent stability and repeatability, achieving a Total Error Band (TEB) better than ±1.5 %FSS over a temperature range of -20...+85 °C. Sensortechnics' SSI pressure sensors use precision digital signal conditioning and provide both analog 0.5...4.5 V output as well as digital I²C or alternatively SPI interfaces at the same time.

The SSI series features an excellent price/performance ratio. Fully welded, media isolated rugged stainless steel constructions allow for high media compatibility with corrosive liquids and gases. Available packaging options include diaphragm versions with weld ring or housings with G 1/8 threaded pressure ports. Sensortechnics' customisation service can provide very fast and flexible mechanical or electronic modifications of its SSI pressure sensor series to fit each customer's application specific requirements.

Important features of the SSI series are:

- Pressure ranges from 200 mbar up to 35 bar gage or absolute
- Total Error Band (TEB) better than ±1.5 %FSS from -20...+85 °C
- Amplified analog and digital output signals at the same time
- Fully welded, media isolated rugged stainless steel construction

Unmatched Sensitivity for Differential Low Pressures

Sensortechnics' new LBA series offers differential low pressure measurement with ranges of 250 and 500 Pa Full Scale. The LBA sensors perform fully analog on-chip CMOS signal conditioning to allow for linear and temperature compensated outputs with high differential pressure resolution of typ. 0.1 % and fast response times of typ. 1 ms.

The LBA sensors feature superior sensitivity and offset stability. The devices are based on thermal flow measurement of gas through a micro-flow channel integrated within the sensor chip. This very narrow channel decreases the flow through the LBA sensor by several magnitudes compared to other flow-based pressure sensors. The extremely low gas flow ensures high immunity to dust contamination and condensation and allows the use of connecting tubes and input filters without the need to recalibrate or correct the output signal. Because the flow impedance is predefined at the sensor chip level the LBA series provides very small and cost-effective PCB-mountable housings.

Sensortechnics' highly sensitive LBA differential pressure sensors are ideal to detect very small pressure differences in many medical respiratory devices such as e.g. ventilators, spirometers, sleep diagnostic equipment, nebulizers and oxygen concentrators/conservers.

Complex Custom Sensing and Fluidic Control Systems

Sensortechnics offers OEM customers complex custom sensing and fluidic control systems for assembly into medical devices, instrumentation equipment and demanding industrial machines. These modules can integrate components such as sensors (e.g. pressure, flow, temperature, humidity), valves, pumps, microcontrollers, reservoirs, accumulators etc. to form compact OEM subsystems. The use of plastic manifolds enables the three-dimensional configuration of flow channels thus eliminating time consuming and error-prone piping procedures. Sensortechnics' integrated systems allow OEM device manufacturers to shorten their design cycle, save development costs and achieve competitive advantages as well as fast innovations to the market.

Sensortechnics' engineers have a vast knowledge and experience in designing fluidic as well as electric circuits and programming microcontrollers and software to handle control signals for sensors and actuators. Analog and digital standard output signals or completely customised interfaces allow for easy integration of the subsystems into OEM devices.

During the development process customer requirements will be converted into a technical specification and build-up of prototypes. Following the verification according to customers' specifications, the design is transferred to Sensortechnics' modern production facilities and finally tested and qualified. Further, Sensortechnics can provide the complete service of all sensing and fluidic control systems for its customers. All processes at Sensortechnics are subject to a quality management system with comprehensive control and documentation requirements which is certified according to ISO 13485:2003 (medical device standard) and ISO 9001:2008.

Continuous contact-free level measurement

Sensortechnics' CLC series uses a new contact-free capacitive sensor technology to continuously measure the fill level of liquids as well as granular or pulverized materials. The miniature sensor can be easily mounted to the outside of a container or vessel and is able to measure through almost any non-metallic wall material. The level sensing range of the standard device is up to 10 cm which can be enlarged in special multi-sensor configurations.

The non-invasive design, with no contact between the sensor and the fluid, eliminates all media compatibility and sterility issues. The device is highly flexible and the user can easily calibrate the sensor to measure to the desired levels, media and application set-up. The CLC series achieves a very high accuracy and reliability due to an additional reference electrode which compensates for all changes in ambient environmental conditions such as temperature and humidity. As an optional safety feature the sensor can be supplied with an extra sensing pad to detect if a container is actually present or not. The CLC sensor offers an analog voltage output as well as a digital interface. Sensortechnics can also provide modifications of its capacitive level sensor based on customer specific requirements.