1. BTEX analyzer with PID detector: chromaPID, Chromatotec, (n.d.). http://www.chromatotec.com/BTEX,analyzer,with,PID,detector,chromaPID-Article-138-ChromaGC-Product-14.html (accessed July 19, 2018).
2. VOC72M, envea Environment SA, (n.d.). http://www.environnement-sa.com/voc72m-the-most-compact-and-robust-analyzer-of-volatile-organic-compounds-on-the-market-launched-at-pollutec/ (accessed July 19, 2018).
3. MODEL GC955-600, ET enviro Technology Services, (n.d.). http://www.et.co.uk/products/air-quality-monitoring/continuous-gas-analysers/synspec-gc955-601-btx/ (accessed July 19, 2018).
4. PetroProTM Portable Gas Chromatograph, INFICON, (n.d.).https://products.inficon.com/en-us/nav-products/product/detail/petropro-portable-gas-chromatograph/ (accessed July 19, 2018).
5. ToxiRAE Pro PID, RAE Systems, (n.d.). https://www.raesystems.com/products/portable-single-gas-detection/toxirae-pro-pid-voc-single-gas-detection (accessed July 19, 2018).