The Spiralarm was one of the first detectors to combine flame detection with electric signalling. If gas was present, the flame would grow, heating a bimetal strip which would operate a set of contacts to create a circuit, turning on a electric lamp and setting off an alarm. It would be set to a specific level and if gas exceded it, the alarm would sound.
Analytical cookies are used to understand how visitors interact with the website. These cookies help provide information on metrics the number of visitors, bounce rate, traffic source, etc.
The _ga cookie, installed by Google Analytics, calculates visitor, session and campaign data and also keeps track of site usage for the site's analytics report. The cookie stores information anonymously and assigns a randomly generated number to recognize unique visitors.
Set by Google to distinguish users.
Installed by Google Analytics, _gid cookie stores information on how visitors use a website, while also creating an analytics report of the website's performance. Some of the data that are collected include the number of visitors, their source, and the pages they visit anonymously.
AddThis sets this cookie to track page visits, sources of traffic and share counts.
YouTube sets this cookie via embedded youtube-videos and registers anonymous statistical data.
1 year 1 month
Set by addthis.com to determine the usage of addthis.com service.