... 100% Vol 1. Summarize GD80 series portable intelligent gas detector adopts the most advanced large scale integrated circuit technology, ... used in petroleum, chemical, environmental protection, metallurgy, refining, gas transmission and distribution, biological medicine, agriculture, etc 2. ... Type or Pump suction method Concentration unit:ppm,%VOL,%LEL,mg/m3 Acousto-optic alarm means:, vibration Working ...