A Smart Rig for Calibration of Gas Sensor Nodes

Abstract

Electrochemical gas sensors require regular maintenance to check and secure proper functioning. Standard procedures usually involve testing and recalibration of the sensors, for which working environments are needed. Periodic calibration is therefore necessary to ensure reliable and accurate measurements. This paper proposes a dedicated smart calibration rig with a set of novel features enabling simultaneous calibration of multiple sensors. The proposed calibration rig system comprises a gas mixing system, temperature control system, a test chamber, and a process-control PC that controls all calibration phases. The calibration process is automated by a LabVIEW-based platform that controls the calibration environment for the sensor nodes, logs sensor data, and best fit equation based on interpolation for every sensor on the node and uploads it to the sensor node for next deployments. The communication between the PC and the sensor nodes is performed using the same IEEE 802.15.4 (ZigBee) protocol that the nodes also use in field deployment for air quality measurement. The results presented demonstrate the effectiveness of the sensors calibration rig.

Designing State‐of‐the‐Art Gas Sensors: From Fundamentals to Applications

“…Analog-to-digital conversion, signal processing, and data interpretation can all be used to determine gas concentrations or detect specific gas instances. [60]…”

“…Using appropriate data acquisition methods, it's necessary to collect and evaluate sensor output. Analog‐to‐digital conversion, signal processing, and data interpretation can all be used to determine gas concentrations or detect specific gas instances [60] …”

A Review of State-of-the-Art Low-Cost Sensors for Detection of Indoor Air Pollutants that Correlate with Health

“…Four major types of automated calibration approaches have been developed and tested till date: a) Uni-Gas Uni-Sensor Calibration; b) Uni-Gas Multi-sensor ENB Calibration; c) IoT-based Networked Multi-Gas ENB Calibration; and d) Climate Smart Heterogeneous ENB Calibration. The recent work realized a plethora of efforts made in gas sensors calibration [114][115][116][117][118][119][120][121][122][123][124][125][126][127] presented in Figures 23-26.…”

An open‐source tool for evaluating calibration techniques used in low‐cost air pollutant monitors

“…Therefore, the application of pollutant concentration values obtained with random temperature and RH can compromise the performance of the regressor, since a non‐ideal data set is submitted in the model training process. To ensure that the temperature and RH are stable within the monitoring systems in field measurements, some authors focus on the use of controlled heaters coupled inside the equipment [11].…”

“…It was also identified in the literature review that this type of work typically focuses on implementing some specific algorithms to create classification or regression models under very ideal laboratory conditions and taking these metrics into field calibrations [10,11]. Ref.…”