Figure 2

Sensitivity and response of the ammonia sensor. (a) Calibration plots for ammonia sensors A, B, C, and D in a concentration range between 3 and 30,000 μg/l with a view to the ammonia toxicity level in fish of 25 μg/l (grey line) (mean values from 6 sensor layers); (b) time resolved signal response (red graph) and calculated concentrations (blue graph) based on sensor B; (c) response and recovery response of sensor B between 10 and 100 μg/l ammonia in 100 mM phosphate buffer at pH 7.2.