การล้างเครื่องจักร

การล้างเครื่องจักร

ผลลัพธ์ (อังกฤษ) 1:

washing machine

ผลลัพธ์ (อังกฤษ) 2:

Washing machine

ผลลัพธ์ (อังกฤษ) 3:

1. Standard samplesAll VOCs (acetone, isopropyl alcohol, hexane, 2-butanone, 2-butanol, benzene, toluene, butyl acetate,propylene glycol methyl ether acetate (PGMEA), m,pxylene, and o-xylene) were obtained from Chemservice(West Chester, PA, USA) with purity above 99.5%. Gas standards were prepared by injecting a certain amount of the liquid standards containing a mixture of the 12VOCs into a Model 232 Tedlar (SKC Inc., USA) sampling bag filled with a known amount of helium gas as the dilution gas. In order to simulate the humidity in the workplace air, the dilution gas had been passed through deionized water before filling the sample bag. Water waspurified by a Millipore Milli-Q instrument on the basis of reverse osmosis, charcoal adsorption, and UV irradiation. Gas standards were prepared with a relative humidity of 80 ± 5%.The concentration of a VOC in a gas mixture can be calculated from where Cppmv is the concentration of the VOC sample (ppmv), 22.4 is molar volume of gas at STP (l/mol), q isthe density of the liquid sample injected (g/ml), Vl is the volume of the liquid sample injected (ml), M is the molecular weight of the analyte (g/mol), V is the total volume of the dilution gas (l), T is temperature (K), and P is pressure (Torr). The concentration of each VOC inthe gas standards was prepared at a level of approximately 100 ppmv by this static method