5.1 The butane activity as determined by this test method is a measure of the ability of an activated carbon to adsorb butane from dry air under specified conditions. It is useful for the quality control and evaluation of granular activated carbons. The butane activity is an indication of the micropore volume of the activated carbon sample. This activity number does not necessarily provide an absolute or relative measure of the effectiveness of the tested carbon for other adsorbates or at other conditions of operation.

5.2 The butane activity test can be used as a non-ozone depleting substitute for the carbon tetrachloride activity test in Test Method D3467. Fig. 1 shows an experimental correlation of activity values obtained using the two adsorbates.

Note 1: This test has not been designed for use with powdered activated carbon, but it has been used successfully when the flow rate or time are adjusted or the sample volume is decreased to keep the pressure drop at an acceptable value.

1.1 This test method covers determination of the activation level of activated carbon. Butane activity (BA) is defined herein as the ratio (in percent) of the mass of butane adsorbed by an activated carbon sample to the mass of the sample, when the carbon is saturated with butane under the conditions listed in this test method.

1.2 The values stated in SI units are to be regarded as standard. No other units of measurement are included in this standard.

1.3 This standard does not purport to address all of the safety concerns, if any, associated with its use. It is the responsibility of the user of this standard to establish appropriate safety and health practices and determine the applicability of regulatory limitations prior to use. For a specific warning statement, see 7.1.