Measuring Hydrogen in Indoor Air with a Selective Metal Oxide Semiconductor Sensor: Dataset

The dataset was created at the Lab for Measurement Technology (Saarland University). It consists of the resistance values of two temperature-modulated semiconductor metaloxide gas sensors (SGP30, Sensirion AG, Switzerland), target values from the calibration and values from the field tests of the reference measurement systems GC-RCP (Peak Performer 1, Peak Laboratories LLC, USA), TD-GC-MS (Markes International, UK; Thermo Fisher Scientific Inc., USA) and X-pid 9500 (Dräger Safety AG & Co KGaA, Germany).

Temperature cycle: The TC consists of 10 steps at 400 °C with a duration of 5 s each, followed by different low-temperature steps, which are set to 100, 125, 150, 175, 200, 275, 300, 325, 350 and 375 °C with a duration of 7 s each resulting in a total duration of the TC of 120 s.

The whole dataset can be divided into different laboratory measurements and field tests. The chronological sequence of the measurements is as follows:

1. Initial calibration (11 days)
2. 1^st field test period (4 weeks)
3. 1^st Recalibration (11 days)
4. 2^nd field test period (3 weeks)
5. 2^nd Recalibration (5 days)

Calibration: The calibration measurements were done with the custom-built gas mixing apparatus (GMA) from the Lab for Measurement Technology, where mixtures of the following substances are generated: Acetone, Toluene, Formaldehyde, Ethanol, Hydrogen, Carbon Monoxide, and Humidity. The background concentration ranges for the difference substances consists of the following concentrations and the distribution is based on Latin Hypercube Sampling:

For the calibration, there are also gas mixtures in which the concentration ranges for individual substances have been extended to 1000 ppb for Acetone, Toluene and Ethanol and to 4000 ppb for Hydrogen.

Field tests: The field tests were performed in a regular office of our building. During the sensors are running continuous, release tests via evaporation of a certain volume of different VOCs were performed. As often as possible measurements with reference devices were performed.

Dataset:
The mat-file comprises different datasets:

• sensor0 and sensor1: uid unique identifier
• sensor0 and sensor1: type: sensor type, here both SGP30, multi-pixel gas sensor
• sensor0: conditioned 0: installed as delivered
• sensor1: conditioned 1: pre-treated with Octamethylcyclotetrasiloxane at 2 ppm over 18 h
• sensor0 and sensor1: resistance0-3: resistance values of the Sensirion SGP30 (4 pixel per sensor) containing 50241 sensor cycles with 2400 data points (@ 10 Hz)
• sensor0_targets and sensor1_targets:
  • time: timestamp at the beginning of each cycle (first data point of the cycle)
  • lab: marked cycles as laboratory measurements
  • fieldtest: marked cycles as fieldtests
  • range: marked cycles for the data evaluation with group number
  • acetone: acetone concentration in ppb
  • ethanol: ethanol concentration in ppb
  • formaldehyde: formaldehyde concentration in ppb
  • toluene: toluene concentration in ppb
  • carbon_monoxide: carbon monoxide concentration in ppb
  • hydrogen: hydrogen concentration in ppb
  • humidity: relative humidity in %RH
  • TVOCppb: sum of all VOC concentations (acetone, toluene, formaldehyde, ethanol) in ppb 
  • TVOCugm3: sum of all VOC concentations (acetone, toluene, formaldehyde, ethanol) in µg/m³
  • limonene: limonene concentration in ppb
  • xylene: xylene concentration in ppb

• reference: RCP hydrogen values during fieldtests with timestamp whenever reference measurements have been done
• reference: GCMS toluene values during fieldtests with timestamp whenever reference measurements have been done
• reference: Xpid toluene, acetone, xylene and isopropyl values during fieldtests with timestamp whenever reference measurements have been done

An exact description of the measurement setup and its results can be found in the open access articles:

Baur, T.; Amann, J.; Schultealbert, C.; Schütze, A. Field Study of Metal Oxide Semiconductor Gas Sensors in Temperature Cycled Operation for Selective VOC Monitoring in Indoor Air. Atmosphere 2021, 12, 647. https://doi.org/10.3390/atmos12050647

Schultealbert, C.; Amann, J.; Baur, T.; Schütze, A. Measuring Hydrogen in Indoor Air with a Selective Metal Oxide Semiconductor Sensor. Atmosphere 2021, 12, 366. https://doi.org/10.3390/atmos12030366

Other publications based on this dataset are the following open access articles:

Robin, Y.; Amann, J.; Baur, T.; Goodarzi, P.; Schultealbert, C.; Schneider, T.; Schütze, A. High-Performance VOC Quantification for IAQ Monitoring Using Advanced Sensor Systems and Deep Learning. Atmosphere 2021, 12, 1487. https://doi.org/10.3390/atmos12111487

Amann, J., Baur, T., Schultealbert, C. , Schütze, A. Bewertung der Innenraumluftqualität über VOC-Messungen mit Halbleitergassensoren - Kalibrierung, Feldtest, Validierung. tm - Technisches Messen, 2021, 88, 1. https://doi.org/10.1515/teme-2021-0058

Schütze, A.; Amann, J., Baur, T., Schultealbert, C. Messung von VOCs in Innenräumen mit low-cost Sensorik und Vergleich mit analytischen Messungen. Umweltbundesamt, UMWELT UND GESUNDHEIT 01/2022, Sonderheft WaBoLu-Innenraumtage 2021, ISSN 1868-4340.

Amann, J., Schütze, A. Kontinuierliche VOC-Messung in Innenräumen mit low-cost MOS-Sensorik. Jahresmagazin Mess- und Sensortechnik 2021/2022, Institut für wissenschaftliche Veröffentlichungen (IWV), 2021, ISSN: 1618-8357