The scope of this project was to create a mesh-sensor network using 802.15 Xbee radios that communicated data back to a central server. This data was correlated to physical building location and part of an alerting service. The sensors were MQ2 sensors capable of measuring subtle grades of gas presence in a lab and in the real world. Additional website and GPS relevant tracking were provided making this an end-to-end project developed by ITM graduate students.
Humans are wired so we only react to threats we can sense. We’re not so good at responding to threats we can’t see, hear or touch; especially as it pertains to pollution of air and water, toxic chemicals in products we buy and climate pollution. Perlstein Hall at Illinois Institute of Technology uses natural gas to supply much of its power. A year ago, a methane gas leak started in Perlstein Hall and everyone in the building was quite oblivious about what was happening. The leak was not made known to everyone until a couple hours after it had started, and after a while, students were asked to evacuate the building. Lectures, meetings and office staff were disrupted during this period. Research shows that methane is extremely flammable even in low concentrations when mixed with other chemicals, and for this reason we decided to create Gas Detectors.
Problem worth solving
Gases we use in our daily lives aren’t dangerous when they are sealed inside pipes and used in the right way. In the United States, natural gas is used for power and heating and therefore prevalent in most homes and buildings. The problem occurs when gases escape their containers as it is difficult to detect and can be very dangerous. With gas commonly used, difficult to detect and potentially dangerous, we wanted to provide a safe detection solution similar to fire and smoke detectors.
Undetected gas leaks can cause headache, dizziness, upset stomach, vomiting, feeling tired, fuzzy vision, and even death. These symptoms arise in the initial stages of a leak but worsen exponentially and they could lead to adverse circumstances causing serious organ damage or even death.
Our solution: The Gas Leak Detector – One device to monitor all gas safety problems
Focusing on the essential need for gas monitoring and protection, we derived a robust and reliable solution. Using some basic computing devices and advanced computing configurations, we created a series of devices to collect, transmit and display data needed for monitoring gas.
Our unique setup consists of two main components working to gather the information and transmit it to a web presence. We considered the important factors for monitoring of gases through our platform and included the best sensing techniques with enhanced reliability for providing a robust solution.
To evaluate the performance of gas sensing methods or gas sensors, several indicators were considered:
• Sensitivity: the minimum value of target gases' volume concentration when they could be detected
• Selectivity: the ability of gas sensors to identify a specific gas among a gas mixture
• Response time: the time period from when gas concentration reaches a specific value to when a sensor generates a warning signal
• Energy consumption
• Reversibility: whether the sensing materials could return to its original state after detection
• Adsorptive capacity which also affects sensitivity and selectivity
Gas sensors designed for the market must guarantee the stability of their operation and should exhibit a stable and reproducible signal for a period of time. There are several factors leading to a gas sensor's instability (extracted and concluded from):
• Design errors (which should be avoided)
• Structural changes, such as variations of grain size or grain network
• Phase shifts, which usually refers to the segregation of additives doped with sensing materials
• Poisoning triggered by chemical reactions
• Variation of the surrounding environment
In order to solve these problems, the following methods could be considered:
• Using materials with chemical and thermal stability
• Optimizing elemental composition and grain size of sensing materials
• Utilizing specific technology during surface pretreatment of sensors
Unique Value proposition
One of the unique value propositions of our product is that it’s very user friendly and doesn’t require any human action to work. The sensor is left in place and is designed to detect a gas leak and report its location; this continuous monitoring offers enhanced safety. Other gas detection devices require manual operation where a person must carry the sensor to the suspected area of the gas leak. Secondly, our product is inexpensive compared to other gas sensors because our gas sensors are made from very affordable components (Arduino) that are inexpensive, yet very effective, in detecting gas leakage. In addition to detecting, our product also transmits the gas leak information to a website that can be viewed regularly and remotely by the emergency department of any organization. A building floor plan and map visualization on our website display which sensor has detected a gas leakage alerting emergency staff to when and where a gas leak has occurred that could lead to danger for the occupants of that building.