Forensics Detectors Carbon Monoxide Analyzer

Description

This document details the conformance of the Forensics Detectors Carbon Monoxide Analyzer for Landfill to the requirements set by "ALTERNATIVE METHOD FOR THE FIELD DETERMINATION OF CARBON MONOXIDE CONCENTRATION IN LANDFILL GAS WELLHEADS UNDER 40 CFR 63, SUBPART AAAA." These requirements were approved on 09/14/2021.

Gas Source

Calibration gas bottles used in this analysis are certified to have an analytical uncertainty of +/- 2%, verified by direct comparison to calibration standards traceable to the National Institute of Standards and Technology (N.I.S.T) weights and/or N.I.S.T Gas Mixture reference materials. Supplied by GASCO and Ideal Calibrations.

Calibration Gas Concentrations:

• Low CO gas: 4.9ppm (for linearity)
• Medium CO gas: 192ppm (for linearity)
• Medium CO + H2 gas: 206.4ppm (CO) + 204.8ppm (H2) (for cross sensitivity)
• High CO gas: 916ppm (for linearity)

Location

Testing and calibration undertaken at Forensics Detectors laboratory in Los Angeles, CA, USA.

Calibration Conditions

Typical calibration was undertaken at ambient conditions:

• Temperature: 72°F
• Humidity: 60 %RH

Procedure

As specified in "ALTERNATIVE METHOD FOR THE FIELD DETERMINATION OF CARBON MONOXIDE CONCENTRATION IN LANDFILL GAS WELLHEADS UNDER 40 CFR 63, SUBPART AAAA." These requirements were approved on 09/14/2021.

Manufacturer Documentation

Linearity Verification

7.2.1 Select one cell from a batch of cells of the same model and make obtained from a CO cell supplier.

7.2.1.1 Introduce a standard to the selected CO cell at a low, mid, and high concentration within the cell span established by the CO cell supplier.

7.2.1.2 Determine the best fit line between the standard gases. The line must have an R-squared greater than or equal to 0.975 to be considered linear.

7.2.2 Verify the linearity of a specific model/make of CO cell any time a new model/make CO cell is obtained from a supplier, or the supplier has changed the specifications of the CO cell.

Instrument Manufacturer Information Requirements

The instrument manufacturer must provide or make available information as follows:

• 7.2.3 A statement pertaining to the instrument range based on the CO cell supplier's specification.
• 7.2.4 A statement that the linearity of the CO cell used in the instrument has been verified.
• 7.2.5 A statement of the interference compensation limit.
• 7.2.6 A statement certifying that annual instrument performance checks have been conducted and the instrument passes those checks.

Model FD-600-CO-LAND Specifics

• The model FD-600-CO-LAND has a carbon monoxide detection range from 0 to 1000ppm.
• The model FD-600-CO-LAND linearity has been tested and verified.
• The model FD-600-CO-LAND interference compensation to H2 has been tested and verified.
• The model FD-600-CO-LAND is equipped with a H2 compensated CO sensor that measures and reduces H2 interference to less than 2.5% of the standard gas concentration applied.

Calibration Data Table:

Linear Regression Analysis Description:

A linear regression analysis was performed for the FD-600-CO-LAND. The graph shows Carbon Monoxide NIST Traceable Source (Calibration Gas Applied) on the x-axis and Analyzer Data (ppm) on the y-axis. The regression line is represented by the equation y = 0.996x + 7.1091, with an R² value of 0.9993, indicating strong linearity.

Interference Compensation Test:

Analyzer Data for Interference Test:

• Analyzer Data: 192ppm
• Interference: 196ppm

Performance Checks and Recommendations:

• The model FD-600-CO-LAND passes all instrument performance checks when manufactured and prior to shipping.
• Forensics Detectors recommends customers perform calibration between 6 to 12 months on an annual basis.