Teledyne 200AU instruction manual Certification Procedures of Working Standards, Permeation Tubes

Teledyne API Model 200AU NOX Analyzer Instruction Manual, 02293, Rev. F

Table 7-17: NIST-SRM's Available for Traceability of Calibration and Audit Gas Standards

NIST-SRM4	Type	Size, at STP	Nominal
			Concentration
1683a	Nitric oxide in N2	870	50 ppm
1684a	Nitric oxide in N2	870	100 ppm
1685a	Nitric oxide in N2	870	250 ppm

Permeation Tubes

NIST-SRM4		Permeation rate,	Concentration, ppm
	Type		at flow rates of:
		ug/min	1 L/min/5 L/min
1629	Nitrogen dioxide	1.0	0.5/0.1

Cylinders of working gas traceable to NIST-SRM's (called EPA Protocol Calibration Gas) are also commercially available (from sources such as Scott Specialty Gases, Scott-Marin etc.).

7.6.12 Certification Procedures of Working Standards

The NO content of the NO working standard must be periodically assayed against NIST-traceable NO or NO2 standards. Any NO2 impurity in the cylinder must also be assayed. Certification of the NO working standard should be made on a quarterly basis or more frequently, as required.

Procedures are outlined below for certification against NO traceable standard. The simplest and most straightforward procedure is to certify against a NO standard.

NOTE

If the assayed concentration of NO2 impurity in the NO cylinder, [NO2]imp, is greater than the 1 ppm value allowed in the calibration procedure, make certain that the NO delivery system is not the source of contamination before discarding the NO standard.

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