Hair Hygrometer, 85mm Diameter Subject_Geology Erlenmeyer Flask with a 250mL

Erlenmeyer Flask with a 250mL capacity and narrow neck is made of heavy-duty borosilicate 3

Balanced wind vane with a steel-pivot bearing assembly and direction indicator mounted on a cast iron base

and triple-parallel plastic wheels at 50mm diameter in low-friction ball-bearing steel frames

Thirteen-coil plug-type resistance box covering 1 ohm to 1000 ohms with 2110 ohms total at plus-or-minus 0

Reel of 250-foot 24 SWG nichrome resistance wire

Hair Hygrometer, 85mm Diameter Subject_Geology Erlenmeyer Flask with a 250mLFor classroom and stockroom room condition monitoring, this hair element hygrometer uses fiber expansion and contraction on an 85 mm dial, running without batteries or external power.