Query: Air temperature and humidity sensor

title: Impact Analysis of Temperature and Humidity Conditions on Electrochemical Sensor Response in Ambient Air Quality Monitoring
abstract: The increasing applications of low cost air sensors promises more convenient and cost effective systems for air monitoring in many places and under many conditions. However, the data quality from such systems has not been fully characterized and may not meet user expectations in research and regulatory uses, or for use in citizen science. In our study, electrochemical sensors (Alphasense B4 series) for carbon monoxide (CO) nitric oxide (NO) nitrogen dioxide (NO2) and oxidants (Ox) were evaluated under controlled laboratory conditions to identify the influencing factors and quantify their relation with sensor outputs. Based on the laboratory tests, we developed different correction methods to compensate for the impact of ambient conditions. Further, the sensors were assembled into a monitoring system and tested in ambient conditions in Hong Kong side by side with regulatory reference monitors, and data from these tests were used to evaluate the performance of the models, to refine them, and validate their applicability in variable ambient conditions in the field. The more comprehensive correction models demonstrated enhanced performance when compared with uncorrected data. One over arching observation of this study is that the low cost sensors may promise excellent sensitivity and performance, but it is essential for users to understand and account for several key factors that may strongly affect the nature of sensor data. In this paper, we also evaluated factors of multi month stability, temperature, and humidity, and considered the interaction of oxidant gases NO2 and ozone on a newly introduced oxidant sensor.

title: Sensor Data Analysis On Monitoring And Control System Of Temperature And Humidity Based On Android In Soybean Seed Storage Room Using Nodemcu
abstract: soybean seeds may be damaged during storage time. Temperature and humidity of soybean seed storage room, is one of the external factors of damage to the seed. The system consists of monitoring and control temperature and humidity in some rooms used as soybean seed storage room samples. This study discusses and perform sensor data analysis using several types of temperature and humidity sensors based on Internet of Things. Sensor nodes generate data and processed by a microcontroller NodeMCU ESP8266, and the results data is then transmitted by the Internet network using MQTT broker and stored in the database. Results data is then analyzed to monitor the condition of soybean seed storage room. SHT30 sensor has the most excellent temperature accuracy of 98, 21% DHT22 sensor has the most excellent moisture accuracy of 95.74% Data sending to the database has a good level of dataloss category for node 1 is 3.39% 4.33% for node 2, and 3.22% for node 3. Air conditioner control system using Android can keep the room temperature state in the range of 18 23oC and humidity of 40 60% with an air conditioning remote control setting at 20oC on an area of 36 m2.

title: Detection of air temperature, humidity and soil pH by using DHT22 and pH sensor based Arduino nano microcontroller

title: Effect of Relative Humidity and Air Temperature on the Results Obtained from Low Cost Gas Sensors for Ambient Air Quality Measurements
abstract: Using low cost gas sensors for air quality monitoring promises cost effective and convenient measurement systems. Nevertheless, the results obtained have a questionable quality due to different factors that can affect sensor performance. The most discussed ones are relative humidity and air temperature. This investigation aimed to assess the behavior of B4 series low cost gas sensors from Alphasense for measuring CO, NO, NO2, and O3 for different levels of relative humidity and temperature. These low cost gas sensors were tested for six relative humidity levels from 10% to 85% with increasing steps of 15% and four temperature levels of 10 degC, 25 degC, 35 degC, and 45 degC against reference instruments in the laboratory. The effect of these parameters on low cost gas sensors was quantified in laboratory from which a correction algorithm was calculated, which was then applied to the field data. The applied algorithm improved the data quality of the low cost gas sensors in most of the cases. Additionally, a low cost dryer was assessed to reduce the influence of these factors on the low cost gas sensors, which also proved to be suitable to enhance the data quality.

title: Temperature and humidity calibration of a low cost wireless dust sensor for real time monitoring
abstract: This paper introduces the design, calibration, and validation of a low cost portable sensor for the real time measurement of dust particles within the environment. The proposed design consists of low hardware cost and calibration based on temperature and humidity sensing to achieve accurate processing of airborne dust density. Using commercial particulate matter sensors, a highly accurate air quality monitoring sensor was designed and calibrated using real world variations in humidity and temperature for indoor and outdoor applications. Furthermore, to provide a low cost secure solution for real time data transfer and monitoring, an onboard Bluetooth module with AES data encryption protocol was implemented. The wireless sensor was tested against a Dylos DC1100 Pro Air Quality Monitor, as well as an Alphasense OPC N2 optical air quality monitoring sensor for accuracy. The sensor was also tested for reliability by comparing the sensor to an exact copy of itself under indoor and outdoor conditions. It was found that accurate measurements under real world humid and temperature varying and dynamically changing conditions were achievable using the proposed sensor when compared to the commercially available sensors. In addition to accurate and reliable sensing, this sensor was designed to be wearable and perform real time data collection and transmission, making it easy to collect and analyze data for air quality monitoring and real time feedback in remote health monitoring applications. Thus, the proposed device achieves high quality measurements at lower cost solutions than commercially available wireless sensors for air quality.

title: A Highly Sensitive FET Type Humidity Sensor with Inkjet Printed Pt In2O3 Nanoparticles at Room Temperature
abstract: In this work, Pt doped In 2 O 3 nanoparticles (Pt In 2 O 3 were inkjet printed on a FET type sensor platform that has a floating gate horizontally aligned with a control gate for humidity detection at room temperature. The relative humidity (RH) sensing behavior of the FET type sensor was investigated in a range from 3.3 (dry air in the work) to about 18% A pulsed measurement method was applied to the transient RH sensing tests of the FET type sensor to suppress sensor baseline drift. An inkjet printed Pt In 2 O 3 resistive type sensor was also fabricated on the same wafer for comparison, and it showed no response to low RH levels (below 18% In contrast, the FET type sensor presented excellent low humidity sensitivity and fast response (32% of response and 58 s of response time for 18% RH) as it is able to detect the work function changes of the sensing material induced by the physisorption of water molecules. The sensing mechanism of the FET type sensor and the principle behind the difference in sensing performance between two types of sensors were explained through the analysis on the adsorption processes of water molecules and energy band diagrams. This research is very useful for the in depth study of the humidity sensing behaviors of Pt In 2 O 3 and the proposed FET type humidity sensor could be a potential candidate in the field of real time gas detection.

title: Simultaneous temperature and humidity measurements in a mechanical ventilator using an optical fibre sensor
abstract: An optical fibre sensor for simultaneous temperature and humidity measurements consisting of one fibre Bragg grating (FBG) to measure temperature and a mesoporous film of bilayers of Poly(allylamine hydrochloride)(PAH) and silica (SiO2) nanoparticles deposited onto the tip of the same fibre to measure humidity is reported. The hygroscopic film was created using the layer by layer (LbL) method and the optical reflection spectra were measured up to a maximum of 23 bilayers. The temperature sensitivity of the FBG was 10 pm/degC while the sensitivity to humidity was 1.4x10 12 W %RH) using 23 bilayers. The developed sensor was tested in the mechanical ventilator and temperature and humidity of the delivered artificial air was simultaneously measured. Once calibrated, the optical fibre sensor has the potential to control the absolute humidity as an essential part of critical respiratory care.

title: Temperature modulated graphene oxide resistive humidity sensor for indoor air quality monitoring.
abstract: In this paper we present a temperature modulated graphene oxide (GO) resistive humidity sensor that employs complementary metal oxide semiconductor (CMOS) micro electro mechanical system (MEMS) micro hotplate technology for the monitoring and control of indoor air quality (IAQ) GO powder is obtained by chemical exfoliation, dispersed in water and deposited via ink jet printing onto a low power micro hotplate. Atomic force microscopy (AFM) and transmission electron microscopy (TEM) show the typical layered and wrinkled morphology of the GO. Raman spectroscopy, X ray photoelectron spectroscopy (XPS) and Fourier transform infra red (FTIR) spectroscopy indicate that the GO flakes possess a significant number of oxygen containing functional groups (epoxy, carbonyl, hydroxyl) extremely attractive for humidity detection. Electro thermal characterisation of the micro hotplates shows a thermal efficiency of 0.11 mW per degC, resulting in a sensor DC power consumption of only 2.75 mW at 50 degC. When operated in an isothermal mode, the sensor response is detrimentally affected by significant drift, hysteretic behaviour, slow response/recovery times and hence poor RH level discrimination. Conversely, a temperature modulation technique coupled with a differential readout methodology results in a significant reduction of the sensor drift, improved linear response with a sensitivity of 0.14 mV per resolution below 5% and a maximum hysteresis of 5% response and recovery times equal to 189 49 s and 89 5 s, respectively. These performance parameters satisfy current IAQ monitoring requirements. We have thus demonstrated the effectiveness of integrating GO on a micro hotplate CMOS compatible platform enabling temperature modulation schemes to be easily applied in order to achieve compact, low power, low cost humidity IAQ monitoring.

title: Computational Fluid Dynamics Based Simulation of Crop Canopy Temperature and Humidity in Double Film Solar Greenhouse
abstract: The microenvironment of the crop area in a greenhouse is the main factor that affects its growth, quality, and pest control. In this study, we propose a double layer film solar greenhouse microenvironment testing system based on computational fluid dynamics simulations of a celery canopy with a porous medium. A real greenhouse was examined with a sensor system for soil, air, radiation, and carbon dioxide detection to verify the simulation results. By monitoring the internal environment of celery canopies with heights of 0.8 and 1 m during a period of temperature fluctuations, we found the temperature and humidity of the canopy interior changed spatially and differed greatly from the those in the greenhouse under solar radiation conditions. The temperature and humidity of the celery canopy were 4 14degC lower and 10% 30% higher than those of the surroundings. As the canopy grew, the differences in temperature and humidity between the canopy and other parts of the greenhouse increased. The root mean square errors of the temperature and humidity with the 0.8 m high celery canopy were found to be 0.56 and 2.86 during the day and 0.24 and 0.81 at night, respectively; the corresponding values for the 1 m high celery canopy were found to be 0.51 and 2.26 during the day and 0.26 and 0.78 at night. The porous medium model expressed the temperature and humidity characteristics of the celery crop appropriately, and the simulation method was shown to be effective and feasible. With the simulation method proposed in this study, the production of crops in complex microenvironments in greenhouses can be modeled and digitized.

title: Development of Wireless Sensor Network for Monitoring Air Temperature and Soil Moisture on Crops
abstract: Crops including the types of plants that can be grown in dry areas. In dry areas as development land crops, humans attempt to make this by doing irrigation. However, if the amount of water given too much will cause the plants rot and crop failures. Therefore, necessary irrigation system that can be monitored periodically by the farmers to avoid such problems. Wireless sensor networks can be used to monitor land crops. By using the temperature and humidity sensors and soil moisture sensors, soil will be monitored regularly every hour. Data resulting from sensor readings are sent to the database using the GPRS network. The results showed that the prototype of a wireless sensor network on crops have been successfully developed.