INSTRUMENTATION SCIENCE & TECHNOLOGY, vol.34, no.3, pp.347-357, 2006 (SCI-Expanded)
This study deals with a new, relatively economical, and fully automatic spectrophotometer. The most difficult part when working with automatic spectrophotometers is that the same quantities of sample to be analyzed and reagent have to be prepared for each measurement to maintain the reproducibility and accuracy of the measurements. This generally requires the use of very expensive systems ( pumps, selection valves, etc.). In the system proposed here, the flow is gravitational and quantities of sample and reagent are kept constant using level sensors. Simple electrical solenoid valves are used for these processes. The PIC 16F877 microcontroller serves to control the solenoid valves and to save the analytical results. These results are saved on an EEPROM on the electronic card, and may be read directly on an LCD or saved on a PC from the EEPROM. In order to obtain data from remote stations in real time, the results are transmitted as SMS via GSM operators. The system analyzes the Fe(II) ions in the rainwater. By small modifications, it may be used to measure other parameters.