How Smoke Alarms Work. Smoke alarms, which are also called smoke detectors, work by constantly checking the air for traces of the gasses and smoke particles produced by a fire. There are two types of smoke alarms-ionization alarms and photoelectric alarms.moke alarms, which are also called smoke detectors, work by constantly checking the air for traces of the gasses and smoke particles produced by a fire.
Exporting items from OST to PST is the best way to create backup of OST file. If you are connected with Exchange server, you can easily do this via manual method. In other case, you should try some third party tool.
Select the file directories you wish to back up from the list of options, and click Next.. Select the location you wish to save the backup, and click Next.. In this step, you will select the external hard drive as your backup destination. Click Finish to perform the initial system backup.