Kavlico, Moorpark, CA, offers a pressure sensor that is used to provide feedback to the selective catalytic reduction (SCR) after-treatment systems in diesel engines. In these engines, NOx emissions are reduced by urea-air dosing with either 32.5% aqueous urea solution (AUS32) or AdBlue. The sensor monitors the SCR system and helps to determine the appropriate amount of AdBlue reducing agent to be delivered to the catalytic converter module. The sensor is available with a ceramic capacitive sensing element for pressure ranges up to 25 bar and a thin-film TiON sense element for pressure ranges above 25 bar. Output is a linear 0.5–4.5 VDC amplified signal proportional to pressure.