---
kind: "section"
citation: "40 C.F.R. § 63.9323"
title: "40"
number: "63.9323"
heading: "How do I determine the add-on control device emission destruction or removal efficiency?"
url: "https://uscodex.org/cfr/40/63.9323"
---

# §63.9323. How do I determine the add-on control device emission destruction or removal efficiency?


You must use the procedures and test methods in this section to determine the add-on control device emission destruction or removal efficiency as part of the performance test required by [§ 63.9310](/cfr/40/63.9310.md). You must conduct three test runs as specified in [§ 63.7(e)(3)](/cfr/40/63.7.md?p=e-3), and each test run must last at least 1 hour.

- (a) For all types of add-on control devices, use the test methods specified in [paragraphs (a)(1) through (5)](#a-1..a-5) of this section.
  - (1) Use Method 1 or 1A of appendix A to [40 CFR part 60](/cfr/40/part60.md), as appropriate, to select sampling sites and velocity traverse points.
  - (2) Use Method 2, 2A, 2C, 2D, 2F, or 2G of appendix A to [40 CFR part 60](/cfr/40/part60.md), as appropriate, to measure gas volumetric flow rate.
  - (3) Use Method 3, 3A, or 3B of appendix A to [40 CFR part 60](/cfr/40/part60.md), as appropriate, for gas analysis to determine dry molecular weight. The ANSI/ASME PTC 19.10-1981 [Part 10](/cfr/40/part10.md) is an acceptable alternative to Method 3B (incorporated by reference, see [§ 63.14](/cfr/40/63.14.md)).
  - (4) **Use Method 4 of appendix A to 40 CFR part 60, to determine stack gas moisture.**
  - (5) Methods for determining gas volumetric flow rate, dry molecular weight, and stack gas moisture must be performed, as applicable, during each test run.
- (b) Measure total gaseous organic mass emissions as carbon at the inlet and outlet of the add-on control device simultaneously, using either Method 25 or 25A of appendix A to [40 CFR part 60](/cfr/40/part60.md), as specified in [paragraphs (b)(1) through (3)](#b-1..b-3) of this section. You must use the same method for both the inlet and outlet measurements.
  - (1) Use Method 25 of appendix A to [40 CFR part 60](/cfr/40/part60.md) if the add-on control device is an oxidizer, and you expect the total gaseous organic concentration as carbon to be more than 50 parts per million at the control device outlet.
  - (2) Use Method 25A of appendix A to [40 CFR part 60](/cfr/40/part60.md) if the add-on control device is an oxidizer, and you expect the total gaseous organic concentration as carbon to be 50 ppm or less at the control device outlet.
- (c) For each test run, determine the total gaseous organic emissions mass flow rates for the inlet and the outlet of the add-on control device, using Equation 1 of this section. If there is more than one inlet or outlet to the add-on control device, you must calculate the total gaseous organic mass flow rate using Equation 1 of this section for each inlet and each outlet and then total all of the inlet emissions and total all of the outlet emissions.
- (d) For each test run, determine the add-on control device organic emissions destruction or removal efficiency, using Equation 2 of this section:
- (e) Determine the emission destruction or removal efficiency of the add-on control device as the average of the efficiencies determined in the three test runs and calculated in Equation 2 of this section.

## Notes

### Source

Source: 68 FR 28785, May 27, 2003, unless otherwise noted.

### Authority

Authority: 42 U.S.C. 7401 et seq.

### Source

Source: 57 FR 61992, Dec. 29, 1992, unless otherwise noted.