Abstract
In order to develop a compact and low-cost ammonia meter for research, development and evaluation of urea-SCR (Selective Catalytic Reduction) systems for diesel exhaust after-treatment, a prototype optical measurement instrument that consists of a near-infrared (1510nm) fiber-coupled tele-communication diode laser, a multi-pass absorption cell (path length 13.2m), and a compact lock-in detection module was designed and constructed. Calibration tests using room-temperature N2-diluted ammonia sample gases successfully demonstrated the instruments’ linearity over a concentration range from 1ppm to 1600ppm with few percent repeatability and 0.5sec measurement response. The real-time measurement of 50ppm or 1600ppm ammonia diluted with diesel-exhaust was successfully demonstrated.
