Applications

Hydrogen has become an indispensable part of the future energy mix. Our team supported a large research laboratory in the development of new and more efficient fuel cells. In the context of a long-term test carried out over 4 months of a low-temperature polymer electrolyte membrane fuel cell stack, DDM pressure sensors were used in the anode path of the stack. The media compositions at the pressure sensors corresponded to realistic compositions. The involved medium consisted of different concentrations of hydrogen, nitrogen, water vapor and liquid water. The sensing element and pressure connections of our hydrogen-compatible pressure sensors are made from 316l stainless steel. The construction is fully welded and 100% helium leak tested. Each sensor is supplied against a manufacturer declaration for hydrogen use.

The calibration of flow meters is a complex process. Generally speaking, this work is carried out by calibration laboratories having the appropriate technical equipment. In addition to the calibration costs, there is the downtime which may be significant for the customer.

To minimize calibration cost and downtime we developed a customer specific flow calibration rig. The rig is easy to operate and the calibration routine runs automatically. The devices under test (DUT) are flowmeters with ranges up to 30 liters per minute. In order to match calibration fluid with application specific viscosity a special calibration fuild was used. To maintain that viscosity constant, the fluid temperature was controled at a defined level. A variable speed positive displacement pump runs the fluid within a closed loop. Thanks to this pump technology, calibration liquids up to 1,000 cSt may be used. Within the closed loop there is a master flow meter to compare the flow rate readings with the readings from DUT. The handling is easy and requires no special knowledge. Just fit the DUT chose the approbriate calibration routine and press the start buttom. The whole calibration process runs automatically and generates a pass/fail message.

Targets of cost saving and minimizing of downtime where achieved perfectly.

The filling of complex systems requires a sophisticated filling process. A time-optimised process with short cycle times is crucial when it is about economic efficiency. To permit the most rapid filling a number of process steps are required. Their dynamic sequence is determined by the geometry of the unit to be filled and by the fluid properties of the filling medium itself. The typical areas of application are refrigerators, air conditioning systems, heat pumps, systems for braking, cooling, air conditioning, engines, gearboxes, hydraulics or windshield wiper systems. The most important parameter for a short cycle is the process pressure. It is crucial that the pressure sensor is fully integrated within the hydraulic system to respond immediate for any pressure change.

The highlight: Our team has developed miniaturized, customer-specific pressure sensors which permit a direct integration into the filling adapter. In addition to the individual design, the electrical interfaces were designed customer customer specific also.

Depending on the application, pressures can vary between 1 mbar and 125 bar. Fast response time was achieved by flush diaphragm pressure sensing design. Every DDM pressure sensor is equipped with a TEDS memory. The stored data provides default data like TAG number, Serial number, Pressure range, Calibration data which is automatically read at system power up.

Maximised customer benefit: a product with a unique character, exclusively developed and manufactured.

Airbus Defence and Space GmbH

Various experiments of a biological, chemical or physical nature are carried out at an almost daily basis on the ISS space laboratory. Reliabilty of instrumentation is the most important factor. Therefore some of the experiments were tested on Earth under weightlessness simulated. This is why those instruments are temporary brought into the orbit with small rockets. In this context, for the measurement of various electrical and physical parametres, highly precise and reliable sensors are essential. Therefore the DDM pressure sensor PV 15 series was selected and proven to perform as expected.

To be able to operate agricultural cultivation economically, you have to use fertilizers and pesticides.

An excessively high dosage is costly, damages the soil and groundwater.

Liquid fertilizers and pesticides can be applied in a more targeted manner according to the soil behavier.

DDM flow meters are robust and media-resistant. They measure the flow rate in real time, allowing exact dosing at high driving speed and documentation of the amounts of plant agents applied.

Optimised thermal management systems for electric vehicles contribute to an efficient, economical and comfortable mobility. Smart cooling and heat management increases the range of electric vehicle. As a consequence, it also increases their attractiveness and suitability for everyday use. Flow rate and coolant temperature are required to design the system components. DDM coolant sensors measure the flow rate and medium temperature with high accuracy. They are perfect miniaturized to fit even when space is very limited.