Medição de temperatura e umidade relativa utilizando instrumentos digitais endereçáveis.

Abstract

In previous works with 1-wireTM technology only temperature sensors were used on data transmission network with high performance and low cost. In this work it was used the 1-wireTM technology from Dallas Semiconductor to perform temperature and relative humidity data acquisition, through a DS2438 analog to digital (A/D) converter that has a temperature sensor embedded on it. A HIH-3610 capacitive sensor from Honeywell connected to the output of the DS2438 A/D converter was used to measure relative humidity. In this case, the DS2438 served as addresser for the relative humidity sensor. By measurement of the temperature and the voltage on the output of the DS2438 the relative humidity could be determined from a calibration curve furnished by the manufacturer of the HIH-3610 sensor. Results of temperature and relative humidity were compared with results obtained from a reference thermometer and a reference psychrometer, respectively. It was concluded that the degree of agreement between the results was excellent.