With Summer and therefore the BBQ season approaching quickly, I wanted to build a simple handheld and portable device that can detect small gas leaks when connecting LPG gas bottles. When I originally started to investigate how to do this I expected it would be quite challenging, however, I came across the MQ range of sensors which allows you to easily detect a large number of gases. The MQ range of sensors allows the user to detect all manner of gases from Alcohol to Ozone. Follow the chart shown of the sensor code and what gases it can detect. I have chosen the MQ-6 sensor for this project to detect LPG, however, I have designed the circuit to be easily adapted for other sensors. I want the flexibility for users to modify it easily to detect the gas of their choice by using the sensor which correlates to the gas they wish to detect. For example, if you wanted a way to detect the presence of hydrogen gas while charging batteries or for C02 leaks in your home bar system etc, you could just use the sensor that correlates to that specific gas, in this case the MQ-8 or MG-811. I should point out that some sensors need higher or lower heater voltages, so it may not be a straightforward sensor swap. However, the case and code will, for the most part, need minimal modification regardless of the sensor. If this sounds like an ideal project for you find out how to build it here: https://diyodemag.com/projects/sniff_sniff