A special eye-catcher, 2 Polymeters in display cabinet behind glass A Polymeter consisting of a hair hygrometer and a thermometer The measuring element of the hygrometer is human hair that reacts directly to changes in humidity through special treatment. The readings can be used to determine: • Relative humidity • Temperature • Saturation vapour pressure • Dew point temperature • Vapour pressure • Saturation deficit • Frost expectation Both Polymeters are in perfect and good working condition. LUFFT with alcohol thermometer, THIES with mercury thermometer Facet cut glass on both polymeters The hair strands are completely intact The showcase cabinet can be either placed upright or hung. Made in Germany, circa 1970 Measuring range: see photos Dimensions: Polymeters: 240 x 80 x 25 mm Display case: 310 x 205 x 80 mm Weight: LUFFT 135 grams THIES 235 grams With instructions for use in German, English and French Will be sent carefully packed.