Wired and wireless sensor network technologies are adopted in various fields such as fire detection alarm systems, monitoring of temperature and humidity for home automation applications [9], and measurements of toxic gases for environmental selleckchem applications [10]. Our research involves automatic illuminating light control for the adsorption sensitivity of photo-EMF-based ammonia gas sensors using National Instruments (NI) wireless network hardware and protocols. The new autonomous and intelligent systems need to combine information from multiple sensors of different physical characteristics [11�C13].Mathematical and computer methods for control of sensitivity sensors are not generally described in the sensor literature (cf.
[14,15]) because semiconductor gas sensors have only one threshold response and a signal saturation associated with a particular measurement range. Our goal is to change the magnitudes of the threshold response and the measurement Inhibitors,Modulators,Libraries range by controlling illumination intensity.An algorithm to increase the sensibility of a measurement could be implemented with Inhibitors,Modulators,Libraries different software platforms such as Matlab? and LabVIEW? [16,17]. The LabVIEW? program has an advantage when processing real time data for sensor signals. It can be used for sensor simulations and for measurements in real time. Capabilities for simulations and conjugations with different types of hardware enable the design and implementation of an appropriate platform. It supports wire/wireless sensor network communication Inhibitors,Modulators,Libraries devices. The use of the platform can considerably reduce the costs Inhibitors,Modulators,Libraries of both logic design and hardware development.
This article discusses a control problem associated with the adsorption sensitivity of photo-EMF-based ammonia gas sensors and its design and simulation under the LabVIEW? environment in a wireless network.2.?Results and DiscussionPreviously Brefeldin_A we proposed a new type of gas sensors based on the photo-EMF effect, in which adsorption sensitivity can be maximized by controlling the intensity of illumination light corresponding to a wide range of ammonia concentrations [1]. Calibration curves for the ammonia concentration c as a function of photo-EMF magnitude U at different levels of illuminations L are shown in Figure 1, where the sensitivity thresholds for different levels of illumination L (marked by dashed lines) are considerably different.
The photo-EMF signals U are saturated at different concentrations of ammonia for each intensity level L1, L2 and L3. Fitting functions are shown as solid lines.Figure 1.Experimental Tanespimycin data and fitting curves for photo-EMF-based ammonia gas sensors [1] at different levels of illumination L. Thresholds of sensitivity are marked by dashed lines.We found the fitting functions of the experimental data as follows:c(U)=��?[dm(U?b)m?1](1)where U is the magnitude of the photo-EMF, c is the ammonia gas concentration, and a, b, d, m are the fitting parameters.