Oxygen and gas sensors
For platinum based oxygen sensors, the platinum catalyst creates a chemical reaction, which in turn creates a voltage to send a signal whether the oxygen/exhaust mixture is too lean or too rich.
Heraeus offers pure Pt pastes and as an alternative alloyed PtPd pastes.
Pressure and force sensors
Capacitive thick film pressure sensors consist of two ceramic parts bonded together, on which the two electrodes of the capacitor are applied.
Piezo-resistive sensors have a thin ceramic or insulated steel diaphragm. On the diaphragm four printed thick film resistors are connected in a Wheatstone bridge configuration. Working principle is the piezoresistivity of the resistor paste.
We offer for capacitive thick film pressure sensors Au conductors, overglazes and sealing glasses.
The Temperature Coefficient of Resistance (TCR) of platinum at 3927ppm/K is used as a means of measuring temperature.
Special termination and overglaze pastes suitable at high temperatures are offered.