Device for creating a reference humidity

#Applicant claims, under 35 U.S.C. §119, the benefit of priority of the filing date of Aug. 4, 2004 of a German patent application, copy attached, Ser. No. 10 2004 038 020.1, filed on the aforementioned date, the entire contents of which is incorporated herein by reference.

#1. Field of the Invention

#The present invention relates to a device for creating a reference humidity that includes a saturation chamber, a downstream arranged condensate cooler and a measuring chamber connected with the condensate cooler, in which a desired reference humidity can be definitely set by varying pressures and/or temperatures.

#FIG. 1 is a schematic representation of an exemplary embodiment of a device in accordance with the present invention;

#FIG. 2 is a plan view of an embodiment of a condensate cooler to be used with the device of FIG. 1 in accordance with the present invention;

#FIG. 3 is a sectional view of the condensate cooler of FIG. 2; and

#A possible structure of the device in accordance with the present invention for creating reference humidity, which substantially corresponds to the 2-pressure/2-temperature humidity generator already explained above, will first be explained by FIG. 1.

#Dry air or nitrogen at a pressure p1 is conducted here via a pressure regulator 1 through a water bath 2 in a saturating device or a saturation chamber 3 (pre-saturating device) with the temperature ts. As a result, practically water vapor-saturated air at an approximate dewpoint temperature ˜ts at a pressure p1 is obtained. Subsequently, the saturated air is conducted through a heated connecting line V1 at a temperature tv1>ts into a multi-stage condensate cooler 4. The temperature-stabilized condensate cooler 4 is arranged in a highly stable liquid bath 5, and cools the inflowing air to the condenser temperature t1, wherein simultaneously the entire amount of excess water appears as the condensate. As a result, air at a pressure p1 and a temperature t1 is obtained, which is completely saturated with water vapor. The pressure p1 and temperature t1 are measured directly in the condensate cooler 4. In many cases the condensate cooler or condenser is therefore also called a “saturating device”, since its main function is the generation of air saturated with water vapor. In this case the saturating device in the form of the saturation chamber 3 is also called a “pre-saturating device”. Regarding the steps on the part of the condensate cooler 4 used, reference is made to FIGS. 2, 3 and 4a, 4b which follow.

#The saturated air is removed from the condensate cooler 4 through a heated connecting line V2 at a temperature tv2>t1, and is relaxed to the pressure p2 via a heated needle valve 6 with the temperature tp>tv2 and is conducted through a heated connecting line V3 with the temperature tv3>tv2 to a measuring chamber, wherein the gas pressure p2 is measured at the location of the measuring chamber 7.