Dual traces of humidity for a 24-hour period.
Indoor/outdoor humidity over a week.

The Langan Model T12 Dual Electronic Hygrothermograph
is a complete package that combines two highly reliable, well-established
Xeritron^TM Sensors, two equally reliable semiconductor temperature sensors,
-- for details about the Xeritron and its manufacturer, see Hygrometrix, Inc. > --
and the compact and field-tested portable DataBear^TMV Measurer data acquisition system.
Calendar timing and signal-interface electronics optimize the combination.
DOS or MacOS Software is included to read and reset the instrument,
to display the results and to translate into almost any computer format.
Batteries and interface cables come, as well.
Use on receipt!
A solar radiation shield may be ordered as an option, as can very long-life lantern batteries.