Abstract
A simple refractive index sensor for various concentrations of sodium chloride (NaCl) in de-ionized water is proposed and demonstrated. The beam-through technique is used to obtain output voltage of liquids with known refractive indices, namely methanol, de-ionized water, acetone and ethanol. Based on the output voltage of these liquids, the sensor characteristic curve is determined and the refractive indices of 2 % to 12 % sodium chloride concentrations are obtained. A sensitivity and detection limit of 23.07 mV/refractive index unit (RIU) and 2.28 × 10-3 RIU have been derived from measurements, respectively, with a linearity of more than 97 %. The fiber optic sensor is a promising alternative to other well-established methods for the measurement of liquid refractive index due to its simplicity of design, linearity, non-contact sensing, ruggedness and low fabrication cost.
| Original language | English |
|---|---|
| Pages (from-to) | 1035-1038 |
| Number of pages | 4 |
| Journal | Optoelectronics and Advanced Materials, Rapid Communications |
| Volume | 5 |
| Issue number | 10 |
| Publication status | Published - 2011 |
Keywords
- Beam-through technique
- Fiber optic
- Fiber optic displacement sensor
- Refractive index measurement
- Sodium chloride in de-ionized water