Monitoring of Relative Humidity of Soil Using LabVIEW

Abstract

This paper involves the measuring and the monitoring of the humidity and relative humidity using Virtual Instrumentation- LabVIEW. The humidity circuit is built on the NI-ELVIS and the output is indicated by the glowing of the LED at the soil's wet condition. The voltage across the output is acquired using NI DAQ-6008 which is interfaced with the PC. The humidity sensor consists of two probes from the circuit that will be in contact with the soil which senses the moisture content. A graphical block diagram is developed in LabVIEW, which includes the appropriate formula for the calculation of relative humidity (in %) and the output voltage (in volts), which is in the range of (0-2V) for dry soil and (4-7V) for wet condition. The front panel indicates the soil's moist and dry condition with the filtered output waveform graph and the readings are monitored.