(a) Where oxygen is supplied by a constant-flow device only, the rate of flow shall be at least 3 liters per minute for the entire rated service time of the apparatus. (b) Where constant flow is used in conjunction with demand flow, the constant flow shall be greater than 1.5 liters per minute for the entire rated service time. (c) All demand-flow devices shall provide at least 30 liters of oxygen per minute when in the fully open position.§84.95 Service time test; open-circuit apparatus. (a) Service time will be measured with a breathing machine as described in § 84.88. (b) The open-circuit apparatus will be classified according to the length of time it supplies air or oxygen to the breathing machine. (c) The service time obtained on this test will be used to classify the opencircuit apparatus in accordance with §84.53.§84.96 Service time test; closed-circuit apparatus. (a) The closed-circuit apparatus will be classified according to the length of time it supplies adequate breathing gas to the wearer during man test No. 4 described in Table 4 of this subpart. (b) The service time obtained on man test No. 4 will be used to classify the closed-circuit apparatus in accordance with § 84.53.§84.97 Test for carbon dioxide in inspired gas; open- and closed-circuit apparatus; maximum allowable limits. (a) Open-circuit apparatus: (1) The concentration of carbon dioxide in inspired gas in open-circuit apparatus will be measured at the mouth while the apparatus mounted on a dummy head is operated by a breathing machine. An acceptable method for measuring the concentration of carbon dioxide is described in Bureau of Mines Report of Investigations 6865, A Machine-Test Method for Measuring Carbon Dioxide in the Inspired Air of SelfContained Breathing Apparatus, 1966.VerDate 0297 10:06 Dec 23, 1997 Jkt 174160 PO 00000 Frm 00539 Fmt 8010 Sfmt 8010 C:CFR174160.TXT pfrm1254642 CFR Ch. I (10–1–97 Edition)§ 84.98Copies of Report of Investigations 6865 may be inspected or obtained from the NIOSH, Certification and Quality Assurance Branch, 1095 Willowdale Road, Morgantown, WV. 26505–2888. (2) The breathing rate will be 14.5 respirations per minute with a minutevolume of 10.5 liters. (3) A sedentary breathing machine cam will be used. (4) The apparatus will be tested at a temperature of 27 ± 2° C. (80 ± 5° F.). (5) A concentration of 5 percent carbon dioxide in air will be exhaled into the facepiece. (b) Closed-circuit apparatus. The concentration of carbon dioxide in inspired gas in closed-circuit apparatus will be measured at the mouth while the parts of the apparatus contributing to deadair space are mounted on a dummy head and operated by the breathing machine as in paragraphs (a) (1) through (5) of this section. (c) During the testing required by paragraphs (a) and (b) of this section, the concentration of carbon dioxide in inspired gas at the mouth will be continuously recorded, and the maximum average concentration during the inhalation portion of the breathing cycle shall not exceed the following limits:Where the service time isMaximum allowable average concentration of carbon dioxide in inspired air percent by volumeNot more than 30 minutes ............. 2.5 1 hour ............................................ 2.0 2 hours ........................................... 1.5 3 hours ........................................... 1.0 4 hours ........................................... 1.0(d) In addition to the test requirements for closed-circuit apparatus set forth in paragraph (b) of this section, gas samples will be taken during the course of the man tests described in Tables 1, 2, 3, and 4 of this subpart. These gas samples will be taken from the closed-circuit apparatus at a point downstream of the carbon dioxide sorbent, and they shall not contain more than 0.5 percent carbon dioxide at any time, except on apparatus for escape only, using a mouthpiece only, the sample shall not contain more than 1.5 percent carbon dioxide at any time.§84.98 Tests during low temperature operation.(a) The applicant shall specify the minimum temperature for safe operation and two persons will perform the tests described in paragraphs (c) and (d) of this section, wearing the apparatus according to applicant’s directions. At the specified temperature, the apparatus shall meet all the requirements described in paragraph (e) of this section. (b) The apparatus will be precooled at the specified minimum temperature for 4 hours. (c) The apparatus will be worn in the low temperature chamber for 30 minutes, or for the service time of the apparatus, whichever is less. (d) During the test period, alternate 1-minute periods of exercise and rest will be required with the exercise periods consisting of stepping onto and off a box 21.5 cm. (81⁄2 inches) high at a rate of 30 cycles per minute. (e)(1) The apparatus shall function satisfactorily at the specified minimum temperature on duplicate tests.
(a) Where oxygen is supplied by a constant-flow device only, the rate of flow shall be at least 3 liters per minute for the entire rated service time of the apparatus. (b) Where constant flow is used in conjunction with demand flow, the constant flow shall be greater than 1.5 liters per minute for the entire rated service time. (c) All demand-flow devices shall provide at least 30 liters of oxygen per minute when in the fully open position.<br>§84.95 Service time test; open-circuit apparatus. (a) Service time will be measured with a breathing machine as described in § 84.88. (b) The open-circuit apparatus will be classified according to the length of time it supplies air or oxygen to the breathing machine. (c) The service time obtained on this test will be used to classify the opencircuit apparatus in accordance with §84.53.<br>§84.96 Service time test; closed-circuit apparatus. (a) The closed-circuit apparatus will be classified according to the length of time it supplies adequate breathing gas to the wearer during man test No. 4 described in Table 4 of this subpart. (b) The service time obtained on man test No. 4 will be used to classify the closed-circuit apparatus in accordance with § 84.53.<br>§84.97 Test for carbon dioxide in inspired gas; open- and closed-circuit apparatus; maximum allowable limits. (a) Open-circuit apparatus: (1) The concentration of carbon dioxide in inspired gas in open-circuit apparatus will be measured at the mouth while the apparatus mounted on a dummy head is operated by a breathing machine. An acceptable method for measuring the concentration of carbon dioxide is described in Bureau of Mines Report of Investigations 6865, A Machine-Test Method for Measuring Carbon Dioxide in the Inspired Air of SelfContained Breathing Apparatus, 1966.<br>VerDate 0297 10:06 Dec 23, 1997 Jkt 174160 PO 00000 Frm 00539 Fmt 8010 Sfmt 8010 C:CFR174160.TXT pfrm12<br>546<br>42 CFR Ch. I (10–1–97 Edition)§ 84.98<br>Copies of Report of Investigations 6865 may be inspected or obtained from the NIOSH, Certification and Quality Assurance Branch, 1095 Willowdale Road, Morgantown, WV. 26505–2888. (2) The breathing rate will be 14.5 respirations per minute with a minutevolume of 10.5 liters. (3) A sedentary breathing machine cam will be used. (4) The apparatus will be tested at a temperature of 27 ± 2° C. (80 ± 5° F.). (5) A concentration of 5 percent carbon dioxide in air will be exhaled into the facepiece. (b) Closed-circuit apparatus. The concentration of carbon dioxide in inspired gas in closed-circuit apparatus will be measured at the mouth while the parts of the apparatus contributing to deadair space are mounted on a dummy head and operated by the breathing machine as in paragraphs (a) (1) through (5) of this section. (c) During the testing required by paragraphs (a) and (b) of this section, the concentration of carbon dioxide in inspired gas at the mouth will be continuously recorded, and the maximum average concentration during the inhalation portion of the breathing cycle shall not exceed the following limits:<br>Where the service time is<br>Maximum allowable average concentration of carbon dioxide in inspired air percent by volume<br>Not more than 30 minutes ............. 2.5 1 hour ............................................ 2.0 2 hours ........................................... 1.5 3 hours ........................................... 1.0 4 hours ........................................... 1.0<br>(d) In addition to the test requirements for closed-circuit apparatus set forth in paragraph (b) of this section, gas samples will be taken during the course of the man tests described in Tables 1, 2, 3, and 4 of this subpart. These gas samples will be taken from the closed-circuit apparatus at a point downstream of the carbon dioxide sorbent, and they shall not contain more than 0.5 percent carbon dioxide at any time, except on apparatus for escape only, using a mouthpiece only, the sample shall not contain more than 1.5 percent carbon dioxide at any time.<br>§84.98 Tests during low temperature operation.<br>(a) The applicant shall specify the minimum temperature for safe operation and two persons will perform the tests described in paragraphs (c) and (d) of this section, wearing the apparatus according to applicant’s directions. At the specified temperature, the apparatus shall meet all the requirements described in paragraph (e) of this section. (b) The apparatus will be precooled at the specified minimum temperature for 4 hours. (c) The apparatus will be worn in the low temperature chamber for 30 minutes, or for the service time of the apparatus, whichever is less. (d) During the test period, alternate 1-minute periods of exercise and rest will be required with the exercise periods consisting of stepping onto and off a box 21.5 cm. (81⁄2 inches) high at a rate of 30 cycles per minute. (e)(1) The apparatus shall function satisfactorily at the specified minimum temperature on duplicate tests.
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