"sling thermometer — A thermometer mounted upon a frame connected to a handle at one end by means of a bearing or length of chain, so that the thermometer may be whirled by hand in order to provide the necessary ventilation."
(prva web referenca - glosar, druga - slika)
Termin "obrtni termometar" pronašla sam na http://pubwww.srce.hr/zuh/od1874/pznan/Geofizk.htm (kontekst: "crpac, obrtni termometar i Ekmanov strujomjer") i verujem da je sasvim prikladan s obzirom na gornji opis iz glosara.