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The NBS Two-Pressure Humidity Generator, Mark 2

1977; The National Institute of Standards and Technology; Volume: 81A; Issue: 1 Linguagem: Inglês

10.6028/jres.081a.010

2376-5704

Saburo Hasegawa, James W. Little,

Thermodynamic and Exergetic Analyses of Power and Cooling Systems

A new humidity calibration facility whi c h uses the two-press ure prin c ipl e for gene rating gas of known humidity has been de veloped at NBS for calibrating and testing hygrome ters.The relat ive humidity range of the two-pressure humidit y gene rator is 3 to 98 percent for ambient tempe ratures -60 ° to 80 °C and test c hamber pressu res 5 to 200 kPa (abso lut e) .Thi s is equival e nt to a nomina l d ew/ frost poi nt ra nge of -80 ° to 80°C.Intercomparison tests we re mad e with the NBS sta ndard grav ime tri c hygrometer over a portion of the gene rator's opera tin g range.The estimated maximum uncert aint y (three sta ndard de viations) is 0 .2percent RH for tempe ratures 0 ° to 80 °C whi c h in units of d ew point corresponds to a n estim ated max imum uncerta int y of 0.04 °C for de w points -35 ° to 80°C.