Automatic assignment of shortcut keys for launching applications or for providing other commands is provided based on the position of corresponding application listings or shortcuts in a menu. About half of the plurality of use-side heat exchangers are preheated or precooled, and the remaining use-side heat exchangers which are not preheated or precooled exchange heat media with use-side heat exchangers that have been preheated or precooled and that are not yet started to operate, suppressing energy consumed for preheating or precooling. Other embodiments are optimized for ER detection in liquid mode, in which the sample is suspended in liquid medium such as water. The information that is collected or imparted may be used for facilitating efficient servicing or maintenance of the transaction terminals.