Humidity is one of the most important factors which must be monitored precisely for the preservation of food
products. A digital humidity meter (hygrometer) has been designed and fabricated by employing a capacitive
sensor. The performance of the digital hygrometer has been studied by comparing its relative humidity readings
with a standard Thermo-hygrometer model HD-600 (Japan) which is microcomputer based and utilizes a polymer
humidity sensor. Statistical analysis was performed to compare the fabricated and the standard hygrometers. The
T test was performed and the value was found to be 1.6875. The standard deviation of the difference of paired
values was 2.212. The performance of fabricated digital hygrometer as compared to the standard hygrometer was
found to lie within 95% confidence interval. The hygrometer was found to be suitable for measuring the relative
humidity. Its easy operation, capability to show direct measurement in short time and low power consumption
make it best replacement of the costly humidity meters which are currently being used in the agricultural products
preservation. This hygrometer can be used in the food industry, particularly in the cold storages where certain
humidity levels are to be monitored. It can be used very effectively to monitor the humidity levels in green houses.
This device can also be used effectively in paper manufacturing plants.
M. Raza Ahmad, Yasir Jamil, Zia ul Haq, Nasir Amin. (2008) An efficient portable and fast response digital humidity meter for use in the preservation of agricultural food products, , Volume-45, Issue-1.
