Hi
this is my first post. i work for the Centre for Sustainable Energy, an energy charity based in Bristol. A key part of our work is in providing energy advice to households. We have recently been involved in a 2 year project partnered with 2 universities to develop an electricity, temperature and humidity sensing application. Known as the Chariot project (https://www.cse.org.uk/projects/view/1277), the idea was to develop a easily deployable set of sensing kit generating data that was readily visualised and viewable through a web app (the latest configuration of this will work with the emon kit). The application aims to help our team of energy advisors work with clients either in their home or over the phone, providing a far more engaging and rich experience.
This we have largely achieved and the project is ongoing as we develop new functionality but the key piece of the jigsaw that is still missing is the ability to reliably sense gas consumption. As much of our work is with vulnerable, low income groups who often underheat their homes (to save money) this is something we want to address (most households in the UK are heated with gas). We have looked at the LOOP system (available through amazon: https://www.amazon.co.uk/Loop-Energy-Electricity-monitors-tracker/dp/B00YNCJB3S/ref=sr_1_1?s=diy&ie=UTF8&qid=1475501168&sr=1-1&keywords=loop+gas+and+electricity ) but this does not suit our 3 week deployment process (you have to send it back to the factory to be reset after each deployment).
We’d also rather use something that sends data to an open database that we can access and that works with the emon set up. So my question is:
Do any on the forum have any suggestions for a robust, low cost proprietary gas monitoring solution?
I’ve seen other posts here on that but they are all quite old and refer to technology that seem like it would require a lot of technical development?. Something new may have come along more recently…
I think the technology for gas meters is moving rather more slowly than electricity meters. Of course, there’s one major problem with a gas meter - there’s no energy source to tap into to provide any intelligence (of the sort we’re used to dealing with!). So you don’t have the luxury of a flashing LED to put a sensor in front of.
To the best of my knowledge, gas meters either have a rotating magnet and/or a reflective patch on the fastest register, or nothing. It is possible to use either a magnetic reed switch or a Hall effect device to sense the magnet passing by, or a retro-reflective optical sensor to see the reflective patch; then providing the meter calibration is known, it’s possible to derive the gas consumption and hence energy usage.
If you have the “nothing” type of meter, I have seen attempts to recognise the dial pointers or digits, either by watching for the pointer to go past or, in one case, using a camera and image processing software to “read” the meter digits or dial positions.
I believe some, by no means all, gas meters have fittings for mounting a sensor that’s available from the manufacturer of the meter.
If there’s a mains power supply available close by the gas meter (or at least reachable by a thinnish cable), then the emonPi and a reed switch would provide a stand-alone solution. Recalibration would be a simple matter of altering the scale factor via a web browser. If no mains is available, then a battery-powered emonTH and the reed switch could transmit the meter pulses to your emonPi located where there is mains power.
I am thinking about knocking together the camera based solution for my own gas meter as it is an ancient one with ft^3 and that high frequency noise emanating from the mechanism! I will probably make my life easy by just using the raspbbery pi camera module as you can pick up the first version for £10!
