초록 ▼

A method of determining bias in a measurement of a constituent concentration level in a sample gas is provided. The method comprises establishing a sample gas flow from an emission stream into a sample gas line of an emissions monitoring system. The method further comprises removing water from the s

A method of determining bias in a measurement of a constituent concentration level in a sample gas is provided. The method comprises establishing a sample gas flow from an emission stream into a sample gas line of an emissions monitoring system. The method further comprises removing water from the sample gas flow and cooling the sample gas flow to a temperature below about 41째 F. to produce a cooled, dried sample gas flow. The constituent concentration level is then determined for the cooled, dried sample gas flow. The method further comprises introducing a span gas having a known span gas constituent concentration level into the sample gas flow to form a combined sample and span gas flow, the span gas being introduced at a desired span gas flow rate. The method still further comprises removing water from the combined sample and span gas and cooling the combined sample and span gas to a temperature below about 41째 F. to produce a cooled, dried, combined sample and span gas flow. A combined sample and span gas constituent concentration level is then determined for the cooled, dried, combined sample and span gas flow. The method also comprises determining a measurement bias using the known span gas constituent concentration level, the sample gas constituent concentration level and the combined sample and span gas constituent concentration level.

대표청구항 ▼

What is claimed is: 1. In an emissions monitoring system, a method of determining bias in a measurement of a constituent concentration level in a sample gas, the method comprising: establishing a sample gas flow from an emission stream into a sample gas line; removing water from the sample gas flow

What is claimed is: 1. In an emissions monitoring system, a method of determining bias in a measurement of a constituent concentration level in a sample gas, the method comprising: establishing a sample gas flow from an emission stream into a sample gas line; removing water from the sample gas flow and cooling the sample gas flow to a temperature below about 41째 F. to produce a cooled, dried sample gas flow; determining the constituent concentration level for the cooled, dried sample gas flow; introducing a span gas having a known spa gas constituent concentration level into the sample gas flow to form a combined sample and span gas flow the span gas being introduced at a desired span gas flow rate; removing water from the combined sample and span gas and cooling the combined sample and span gas to a temperature below about 41째 F. to produce a cooled, dried, combined sample and span gas flow; determining a combined sample and span gas constituent concentration level for the cooled, dried, combined sample and span gas flow; and determining a measurement bias using the known span gas constituent concentration level, the sample gas constituent concentration level and the combined sample and span gas constituent concentration level. 2. A method according to claim 1 further comprising the steps of: measuring a sample flow rate of the cooled, dried sample gas flow; and measuring a combined gas flow rate of the cooled, dried, combined, sample and span gas flow. 3. A method according to claim 2 further comprising the steps of: determining a concentration level of a secondary constituent in the cooled, dried sample gas; correcting the sample flow rate using the secondary constituent concentration level in the cooled, dried sample gas flow; determining a concentration level of the secondary constituent in the combined, cooled, dried span and sample gas flow; and correcting the combined gas flow rate using the secondary constituent concentration level in the combined cooled, dried sample and span gas flow. 4. A method according to claim 3 wherein the secondary constituent is one or more of water, O2 and CO2. 5. A method according to claim 1 further comprising the step of: calculating the desired span gas flow rate using a desired combined sample and span gas constituent concentration level, the sample gas flow rate and the span gas constituent concentration level. 6. A method according to claim 5 wherein the desired combined sample and span gas constituent concentration level to calculated using a predetermined ratio of span gas constituent concentration level to combined sample and span gas constituent concentration level.