--- kind: "section" citation: "30 C.F.R. § 7.89" title: "30" number: "7.89" heading: "Test to determine the particulate index." url: "https://uscodex.org/cfr/30/7.89" --- # §7.89. Test to determine the particulate index. The test shall be performed in the order listed in Table E-3. - (a) **Test procedure.** - (1) Couple the diesel engine to the dynamometer and connect the sampling and measurement devices specified in [§ 7.86](/cfr/30/7.86.md). - (2) **A minimum time of 10 minutes is required for each measuring point.** - (3) **Prior to testing, condition and weigh the particulate filters as follows—** - (i) At least 1 hour before the test, each filter (pair) shall be placed in a closed, but unsealed, petri dish and placed in a weighing chamber (room) for stabilization. - (ii) At the end of the stabilization period, each filter (pair) shall be weighed. The reading is the tare weight. - (iii) The filter (pair) shall then be stored in a closed petri dish or a filter holder, both of which shall remain in the weighing chamber (room) until needed for testing. - (iv) The filter (pair) must be re-weighed if not used within 8 hours of its removal from the weighing chamber (room). - (4) **Run the engine.** - (i) The parameter for fa shall be calculated in accordance with [§ 7.87(a)(3)](/cfr/30/7.87.md?p=a-3). - (ii) The air inlet and exhaust backpressure restrictions on the engine shall be set as specified in [§§ 7.87(a)(3)](/cfr/30/7.87.md?p=a-3) (iii) and (iv). - (iii) The dilution air shall be set to obtain a maximum filter face temperature of 125 °F (52 °C) or less at each test mode. - (iv) The total dilution ratio shall not be less than 4. - (5) The engine shall be at a steady state condition before starting the test modes. - (i) The engine speed and torque shall be measured and recorded at each test mode. - (ii) The data required for use in the particulate index calculation specified in [paragraph (a)(9)](#a-9) of this section shall be measured and recorded at each test mode. - (6) A 1.0 ±0.1 percent CH4, by volume shall be injected into the engine's intake air for category A engines. - (7) Operate the engine at each rated speed and horsepower rating requested by the applicant according to Table E-3 to collect particulate on the primary filter. - (i) One pair of single filters shall be collected or eight multiple filter pairs shall be collected. - (ii) Particulate sampling shall be started after the engine has reached a steady-state condition. - (iii) The sampling time required per mode shall be either a minimum of 20 seconds for the single filter method or a minimum of 60 seconds for the multiple filter method. - (iv) The minimum particulate loading specified in [§§ 7.86(c)(18)](/cfr/30/7.86.md?p=c-18) (iii) or (iv) shall be done. - (v) Test speeds shall be maintained within ±percent of rated speed or ±3 RPM, which ever is greater, except for low idle which shall be within the tolerances set by the manufacturer. - (vi) The specified torque shall be held so that the average over the period during which the measurements are being taken is within ±2 percent of the maximum torque at the test speed. - (vii) The modal weighting factors (WF) given in Table E-3 shall be applied to the multiple filter method during the calculations as shown in [paragraph (a)(9)(iii)(B)](#a-9-iii-B) of this section. - (viii) For the single filter method, the modal WF shall be taken into account during sampling by taking a sample proportional to the exhaust mass flow for each mode of the cycle. - (8) After completion of the test, condition and weigh the particulate filters in the weighing chamber (room) as follows: - (i) **Condition the filters for at least 1 hour, but not more than 80 hours.** - (ii) **At the end of the stabilization period, weigh each filter.** The reading is the gross weight. - (iii) **The particulate mass of each filter is its gross weight minus its tare weight.** - (iv) The particulate mass (PF for the single filter method; PF,i for the multiple filter method) is the sum of the particulate masses collected on the primary and back-up filters. - (v) The test is void and must be rerun if the sample on the filter contacts the petri dish or any other surface. - (9) The particulate index for the mass particulate shall be calculated from the equations listed below— - (i) The following abbreviations shall be: - (ii) When calculating ambient humidity correction for the particulate concentration (Pf part), the equation shall be: - (iii) When the multiple filter method is used, the following equations shall be used. - (A) **Mass of particulate emitted is calculated as follows—** - (B) **Determination of weighted particulate average is calculated as follows—** - (C) Determination of particulate index for the mass particulate from the average of the test modes shall be calculated as follows: - (iv) When the single filter method is used, the following equations shall be used. - (A) **Mass of particulate emitted—** - (B) Determination of particulate index for the mass particulate from the average of the test modes shall be as follows: - (v) When the effective weighting factor, WFE,i, for each mode is calculated for the single filter method, the following shall apply. - (B) The value of the effective weighting factors shall be within ±0.005 (absolute value) of the weighting factors listed in Table E-3. - (b) A particulate index for each requested rated speed and horsepower shall be the value determined in [paragraph (a)(9)(iii)(C)](#a-9-iii-C) of this section for the multiple filter method or [paragraph (a)(9)(iv)(B)](#a-9-iv-B) of this section for the single filter method. - (1) Particulate indices less than 20,000 cfm shall be rounded up to the next 500 cfm. Example: 10,432 cfm shall be listed 10,500 cfm. - (2) Particulate indices greater than 20,000 cfm shall be rounded up to the nearest thousand 1,000 cfm. Example: 26,382 cfm shall be listed 27,000 cfm. ## Notes ### Amendments [61 FR 55504, Oct. 25, 1996; 62 FR 34640, June 27, 1997] ### Source Source: 61 FR 55504, Oct. 25, 1996, unless otherwise noted. ### Authority Authority: 30 U.S.C. 957. ### Source Source: 53 FR 23500, June 22, 1988, unless otherwise noted. ### Amendments [61 FR 55504, Oct. 25, 1996; 62 FR 34640, June 27, 1997]