| 摘要 |
PURPOSE:To decrease the dependency on temp. and to improve the accuracy in a low humidity region by detecting humidity change from the dimensional change of a porous material. CONSTITUTION:A columnar hard ND body 1 is used as the porous material. The body 1 is fixed onto a base plate 2 by means of a holder 5 and a differential transformer 3 (detector) is disposed above the same. The change in the length of the body 1is detected via an actuator 6 by the transformer 3 and is recorded and calculated by a recorder 4, by which the humidity is measured. The body 1 is produced by mixing water with, for example, 80% cement, 10% TSH (calcium aluminate trisulfate hydrate 3CaO.Al2O3.3CaSO4.31-32H2O) and 10% other additives and sheeting the mixture. The size of the porous material with respect to moisture content is determined by the generation and annihilation of the tension of capillarity and therefore the humidity change can be determined from the dimensional change of the body 1 and the measurement of the humidity is made possible. |
