What does "PPM" mean in a gas detector?
PPM is the volume ratio concentration: "PPM" is a way of expressing the concentration of the solution, and PPM means one part per million. For solution: that is, there is 1/1000 ml of solute in 1 liter of aqueous solution, then its concentration is 1 PPM. For gas: One of the ways to express the concentration of pollutants in the ambient atmosphere. Volume concentration expression: the volume of pollutants contained in one million volumes of air, that is, PPM, the gas concentration measured by most gas detectors is volume concentration (PPM), and according to the regulations of our country, especially the environmental protection department , the gas concentration is required to be expressed in units of mass concentration, and our national standards and specifications are also expressed in units of mass concentration. It is manufactured by using some metal oxide semiconductor materials, and at a certain temperature, the electrical conductivity changes with the change of the ambient gas composition.
