S. Matsumoto et S. Toyooka, ESTIMATION OF INITIAL AND RESPONSE-TIMES OF LASER DEW-POINT HYGROMETER BY MEASUREMENT SIMULATION, JPN J A P 1, 34(10), 1995, pp. 5847-5852
The initial and the response times of the laser dewv-point hygrometer
were evaluated by measurement simulation. The simulation was based on
loop computations of the surface temperature of a plate with dew depos
ition, the quantity of dew deposited and the intensity of scattered li
ght from the surface at each short interval of measurement. The initia
l time was defined as the time necessary for the hygrometer to reach a
temperature within +/-0.5 degrees C of the measured dei point from th
e start time of measurement, and the response time was also defined fo
r stepwise dew-point changes of +5 degrees C and -5 degrees C. The sim
ulation results are in approximate agreement with the recorded tempera
ture and intensity of scattered light of the hygrometer. The evaluated
initial time ranged from 0.3 min to 5 min in the temperature range fr
om 0 degrees C to 60 degrees C, and the response time was also evaluat
ed to be from 0.2 min to 3 min.