Abstract: A gas adsorber cell for use in high efficiency gas cleaning systems and the like, and having provision for obtaining a representative and undisturbed sample of the adsorbent material to permit periodic testing of the efficacy of the adsorbent material. The adsorber cell comprises an enclosure including a pair of spaced perforated sheets adapted to receive an adsorbent material therebetween, a sample holder also adapted to be filled with the adsorbent material and having perforated opposite ends, and means for removably mounting the sample holder between the sheets such that a representative portion of the gas passing through the adsorber cell passes through the sample holder. The holder may then be removed to permit periodic testing of the adsorbent material carried therein.