Abstract
Twenty of metal phosphates were investigated as humidity-sensing materials. Eight kinds of metal phosphates including Ti(HPO4)·H2O showed good humidity-sensing characteristics. Treating of Ti(HPO4)·H2O and Ce(HPO4)2·2H2O with NaOH solution considerably lowered the electric resistance, which changed by about three orders of magnitude in the relative humidity range 11 to 94%.
