<title>Long-term renewable sol-gel fluorescent optical fiber pH sensor</title>

Simple Absorption Optical Fiber pH Sensor Based on Doped Sol−Gel Cladding Material

“…A feature to be improved by manipulating the clad porosity, is the risetime from t 1/2 to the plateau, although the first half-time of rise is already convenient. Optimization in this direction as well as design of other similar low-cost absorbance based sol−gel fiber sensors, is in progress …”