Exhaust sensors for large engines have to withstand extremely unfavourable conditions. They are subjected to high temperatures, major temperature fluctuations and extreme vibrations: These are conditions in which a normal temperature sensor does not flourish.

When you add environmental factors such as oil to this, more than just the sensor element needs to be considered. The entire sensor must be designed for the conditions in order to ensure a long service life. Our customer’s concrete requirements included a Pt1000 sensor intended for service on a large diesel engine.

In order to perform this challenging task, we developed and tested a unique sensor:

• The connector was overmolded with hotmelt so that no oil can get into the measuring element.
• The sensor element is protected with construction measures.
• Comprehensive vibration and temperature cycle tests verified the high durability and long service life of our special sensor.

By now, the temperature sensor is used around the world with outstanding results. Solution found – happy customer.

Electromagnetic compatibility (EMC) can really put measurement technology off their stride. As was the case for one of our customers when then requested support from our technical consultants in our sales force. The air conditioning systems used in trains had developed problems with the built-in temperature sensors.

The area of application is very challenging: Temperature and humidity are measured together, there are extremely rapid temperature changes, strong electromagnetic interference interferes with operation and there are constant strong vibrations during operation. The ambient conditions also require protection against a possible risk of fire and explosion in the event of a coolant leak.

We designed a special sensor for these extensive requirements:

• Low installation costs owing to combined temperature and humidity measurement.
• Significantly reduced wiring requirements owing to digital 1-wire bus.
• Thermal decoupling from the place of installation using a special thread made from fibreglass and plastic composite.
• High reliability owing to an integrated protective circuit.
• Compact design.

After development and subsequent type testing in accordance with the railways standards, the sensor went into series production. Solution found – happy customer.

An enquiry for the delivery of temperature sensors reached us from a wind turbine manufacturer. After calculation and generation of a quote, the order was placed with SIKA and the sensors were developed exactly according to the customer’s specifications.

To our great surprise, the first complaints arrived soon after: Sensors were failing in series. In-depth examinations, by the Fraunhofer Institut among others, revealed: A several thousand volt spark was jumping over the sensor and destroying the circuit board coating.

We were finally able to identify the problem through intensive collaboration with the customer: The temperature sensors are used in the rotor blades of wind turbines. Here, as in helicopters, the friction which is present results first in an electrostatic charge and this in a highvoltage discharge which was responsible for the failure of the temperature sensors.

We were able, through appropriate grounding measures and shielding, to make the temperature sensors resistant to the discharge effects. Solution found – happy customer.