The Certified Hygrometer, HTAB-176, is certified to be accurate within +/- 3% RH. The dial indicates the
complete range of 0 to 100% relative humidity. Each instrument has been tested at three different positions
of the dial at temperatures ranging from 32 to 230 F. The calibration and certification are done under ISO-
9001 control. The bi-metallic thermometer on the model HTAB-176 is accurate to 1% of scale w/ a range of
=20 to 100 C and 0 to 210 F. Graduations are 1 for Centigrade and 1% RH.