Packaging and storage—
Preserve in cylinders or in a low-pressure collecting tank.
Labeling—
Where it is piped directly from the collecting tank to the point of use,label each outlet “Nitrogen 97Percent.”
NOTE—Reduce the container pressure by means of a regulator.Measure the gases with a gas volume meter downstream from the detector tube in order to minimize contamination or change of the specimens.
Identification—
The flame of a burning wood splinter is extinguished when inserted into a test tube filled with Nitrogen 97Percent.[NOTE—Exercise caution.]
Odor—
Carefully open the container valve to produce a moderate flow of gas.Do not direct the gas stream toward the face,but deflect a portion of the stream toward the nose:no appreciable odor is discernible.
Carbon dioxide—
Pass 1000±50mLthrough a carbon dioxide detector tube at the rate specified for the tube:the indicator change corresponds to not more than 0.03%.
Carbon monoxide—
Pass 1000±50mLthrough a carbon monoxide detector tube at the rate specified for the tube:the indicator change corresponds to not more than 0.001%.
Sulfur dioxide—
Pass 1000±50mLthrough a sulfur dioxide detector tube at the rate specified for the tube:the indicator change corresponds to not more than 5ppm.
Limit of nitric oxide and nitrogen dioxide—
Pass 500±50mLthrough a nitric oxide-nitrogen dioxide detector tube at the rate specified for the tube:the indicator change corresponds to not more than 2.5ppm.
Limit of oxygen—
Not more than 3.0%of oxygen is present,determined as directed in the Assay.
Assay—
Proceed with Nitrogen 97Percent as directed in the
Assayfor
Nitrogen.The peak response produced by the assay specimen exhibits a retention time corresponding to that produced by an oxygen-helium certified standard (see under
Reagentsin the section
Reagents,Indicators,and Solutions)and is equivalent to not more than 3.0%of oxygen when compared to the peak response of the oxygen-helium certified standard,indicating not less than 97.0%,by volume,of N
2.