Gas Monitoring System
Early notifications of existence of hazard gases may save people live, generally the need of gas monitoring systems is understood if we think about employees, natural catastrophes wars terrorist attaches by chemical gases, also the storage, distribution, and manipulation of such toxics gases present several safety hazards.
In these situations certain area might be corrupted by hazard gases, as most toxic gases cannot be detected by human senses, gas monitoring systems should take place.
It is impossible to generalize as to where the monitoring should be located as this may be different for each situation. The vapor density can indicate if a detector should be mounted near the ceiling or near the floor. Typically, to detect gases heavier than air (e.g. propane) the sensor should be mounted near the floor. To detect gases lighter than air (e.g. methane) the detector should be mounted near the ceiling.
The air flow should also be considered when sitting the detector. Ventilation and other causes of air flow can affect the sitting of the detector.
Devices that are likely to leak should be given consideration when positioning detectors. Boilers, gas tanks and gas cylinders for example, are potential leak points
2. Project Aims
Our aim is to monitor the gas level in any desired place, so that anyone can monitor the gas level displayed on an LCD screen, not only that but also the system will be automated and will take a precaution actions so that it can ensure the human and place safety.
The gas will be displayed on an LCD (liquid crystal display) in four levels in order to make our device more reliable and comfortable to the user and more friendly to use, also the system will activate a fan to recycle the air in that place, if farther increase in gas level is detected a circuit breaker will be activated to cut off the power line to prevent any chance to start a fire.
3.1 Block diagram
The following shows a general block diagram of the system
3.2 Main components list
1. PIC microcontroller (PIC16F876A) (that's best described as the main head unit , this PIC microcontroller where used since all the components in this project need to be interfaced and functioned and the easiest way to do that is to use it, for example in order to inform the any person in the place we have used an LCD screen which much easier to connect it to the PIC rather that dealing with it using interfacing hardware or it will be a waste of time, effort and money, also the PIC has built in peripheral interfaces in case needed and an enough number of Pins for the project requirements).
2. LCD (liquid crystal display) that will be used to display the gas level and any one near the system main plate, we have chosen an LCD screen since it's the best way to inform and alert any person in a friendly and simple clear view.
3. Circuit Breaker (Relay) it is used to cut off the power as precaution, to reduce the opportunity to start a fire, which will be activated on high level of gas detection.
4. Fan it will be used to reduce the amount of gas in the same area at any initial increase of the gas level
3.3 Plan to implement
As shown in the block diagram the reading of the gas sensor will be fed to the microcontroller as analog value then it will be converted in the PIC to digital then it can be displayed on the LCD screen in four levels, the very high level will activate the circuit breaker which is done by a decision made by the PIC and so on as described in the project Idea.
4. Software Approach
Since we are designing a PIC microcontroller based system, first we need tools to program and write the software for the PIC microcontroller, so will use a universal PIC Programmer in order to download the code on the PIC, also we will need to use a PIC code compiler that is efficient and simple to use, so we will use (MikroBasic) compiler since it uses simple basic code also it has various built in libraries for the LCD and many other known interfaces.
1) PICmicro Family Tree", PIC16F Seminar Presentation http://www.microchip.com.tw/PDF/2004_spring/PIC16F%20seminar%20presentation.pdf .
2) Microchip Technology (2008-02-27). "Microchip Technology Delivers Six Billionth PIC® Microcontroller". Press release.