New opto-chemical ammonia sensor

摘要

A new opto-chemical sensor for gaseous ammonia was developed with a detection range from 10 ppm to 200 ppm. For this sensor ammonia sensitive layers were developed and tested for the opto-chemical detection. Indicator dyes were immobilized in different sol-gel-matrices. The most sensitive layer PH is characterized by a high sensitivity in the concentration range 10 ppm ... 100 ppm (MAK value: 50 ppm; MAK: maximum concentration at working place), short reaction times, good reproducibility, long-term stability of the indicator dye in the layer over several months and ammonia durability for concentrations 200 ppm. The developed ammonia sensitive layers were tested in two different opto-chemical sensor systems, the first was based on a new hybrid integrated emitter-receiver-module MORES (Micro-Optical Remissions-/Reflexions- Sensor), the second on a two beam photometer. The results open the field for miniaturized opto-chemical sensors for ammonia in the detection range from 10 ppm to 200 ppm.