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Smart Waste Bin Using AI, Big Data Analytics and IoT
Published in Biswaranjan Acharya, Satarupa Dey, Mohammed Zidan, IoT-Based Smart Waste Management for Environmental Sustainability, 2022
Nivedita Das, Jyotiprakash Panigrahi, Chandrima Roy, Biswaranjan Acharya
A humidity sensor (also known as a hygrometer) is an electronic system that detects humidity in its surroundings and transforms the results into an electrical signal [30]. To determine relative humidity, the maximum amount of humidity for air at the same temperature is compared to the live humidity reading at the same temperature. A humidity sensor detects monitors and records moisture as well as air temperature. The ratio of moisture in the air to the maximum amount of moisture at a given air temperature is called relative humidity [31]. When looking for warmth, relative humidity becomes a key consideration. A humidity sensor (also known as a hygrometer) is shown in Figure 3.12. This sensor measures the percentage of humidity inside or outside of the bin (very near area).
Energy Audits and Instrumentation
Published in Scott Dunning, Larry S. Katz, Energy Calculations & Problem Solving Sourcebook, 2020
The hygrometer is the instrument used to measure humidity. Types: Psychrometer—evaluates wet bulb and dry bulb temperatures which relate directly to relative humidity.Electronic—use sensors whose electrical characteristics (usually resistance or capacitance) change with humidity
Ancillary Measurements
Published in Frank Vignola, Joseph Michalsky, Thomas Stoffel, Solar and Infrared Radiation Measurements, 2019
Frank Vignola, Joseph Michalsky, Thomas Stoffel
Still in use today, the sling psychrometer is used to measure relative humidity. The sling psychrometer measures both the ambient temperature and dew-point temperature, and the relative humidity can be determined using psychrometric charts. Many hygrometers are used to measure relative humidity such as the hair hygrometer, the chilled-mirror dew-point hygrometer, lithium chloride heated condensation hygrometer (dew cell), hygrometers using absorption of electromagnetic radiation, and electrical resistive and capacitive hygrometers. Only the electrical resistive and capacitive hygrometers will be discussed in this book because they lend themselves to automated measurements. For information on the other methods of measuring relative humidity see the CIMO guide (WMO 2014).
Performance assessment of annular fins and cellulose cooling pad on heat transfer enhancement of evaporative heat exchangers using volumetric heat and mass transfer coefficients
Published in Numerical Heat Transfer, Part A: Applications, 2023
The schematic diagram and experimental setup of all four configurations of FCWHX unit are shown in Figures 1–8. Table 1 lists the specifications of main components and instruments used in the setup. Water from the spray water tank is pumped and distributed to the spray nozzles positioned either above the pad or above the heat exchanger depending the configuration of experimental setup. Water at the bottom of the pad or heat exchanger after air-water interaction is collected in a tray. Water from hot water tank is pumped to the inlet header of the heat exchanger and water from the outlet header is returned back to the tank. Air is supplied through the pad in a cross flow configuration. All the measuring instruments are pre-calibrated and their location is indicated in Figures 1, 3, 5, and 7. Glass tube rotameters are used to measure hot water and spray water flow rate, with a measurement uncertainty up to ±3%. Cu-Constantan thermocouples have been used to measure water and air dry bulb temperature, with a measurement uncertainty up to ±0.5 °C. An anemometer with vane probe has been used to measure air velocity, with a measurement uncertainty up to ±5%. A hygrometer is used to measure the temperature and relative humidity of air, with a measurement uncertainty up to ±2.5%.
Numerical analysis-based performance prediction in a direct evaporative cooler used for building cooling
Published in Journal of Building Performance Simulation, 2022
Sampath Suranjan Salins, Shiva Kumar, Ritu Kiran Kartik, S. V. Kota Reddy
Air interacts with the water in the packing in the cross-flow direction. Various instruments are used to measure the required parameters like temperature, velocity and humidity. Dry bulb and wet bulb temperature are measured using a digital thermometer which has an accuracy of ± 0.1°C, resolution of 0.1°C and range of −20°C to 80°C. A hygrometer measures the relative humidity which has accuracy of ± 0.1%, resolution: 0.1%, and range of 0% to 99%. Anemometer measures the air velocity at the inlet and outlet sections having a velocity range of 0.3 to 30 m/s, resolution of 0.1 m/s and accuracy ±5%. Table 2 gives the details of instruments used in humidification.
Experimental investigation on the performance parameters of a helical coil dehumidifier test rig
Published in Energy Sources, Part A: Recovery, Utilization, and Environmental Effects, 2021
Sampath Suranjan Salins, Shahida Anusha Siddiqui, S V Kota Reddy, Shiva Kumar
Relative humidity (RH) is the ratio of the partial pressures of water vapor to the partial pressure of the saturated mixture. Relative humidity mainly depends on the pressure and temperature of the system. For the same quantity of water vapor the relative humidity of cool air is higher than warm air. Hygrometer measures the relative humidity. Using psychrometric chart both relative and specific humidity can be determined. Figures 14 and Figures 15 shows the variation of the change in relative humidity drop with the mass flow rate. Results indicate that there is a significant drop in the RH with mass flow rate. It is mainly due to the increase in mass flow rate and bypass factor gives minimum interaction of air with the coil surface. Figure 14 shows the variation with the various dehumidification coil water temperatures. It is seen that when the dehumidification coil water temperature is lowest maximum decrease in relative humidity occurs. When the temperature is increased to 10°C decrease in relative humidity increases to 50% for the optimum mass flow rate of air. Similarly Figure 15 represents the decrease in Relative humidity for different values of air inlet temperatures. It is seen that for higher air inlet temperatures reduction in the relative humidity is larger. When the air temperature is decreased, difference in RH drops. There is a significant drop in the RH when the inlet air temperature of 40°C is reduced to 30°C and there is a small drop from 30°C to 20°C. Similarly a huge drop in RH is observed when dehumidification coil water temperature is decreased from at 2°C from 5°C, and a small difference from 5°C to 10°C. Figures 16 and Figures 17 shows the temperature drop with the mass flow rate of air.