【国外标准】 Standard Test Method for On-site Screening of Heterotrophic Bacteria in Water (Withdrawn 2004)

1.1 This screening test method covers the detection and enumeration of bacteria contained in a water sample employing a commercial device specifically designed for that purpose. This test method applies only to the enumeration of those viable bacteria that will grow under the test conditions specified (for example, medium, temperature, time, etc.). It is not applicable to the detection of anaerobic bacteria. 1.2 No bacterial culture technique can enumerate all the viable bacteria in a sample, since bacteria occur singly, in pairs, chains, or clusters and no single set of growth conditions or media can satisfy the physiological requirements of all bacteria in a sample. Therefore, this test method cannot provide a total bacterial count, but can only strive to achieve a relative count of viable aerobic and facultative anaerobic bacteria present in a sample. 1.3 The test method applies to samples in which the number of culturable bacteria per millilitre exceeds at least 10 and no more than 160 bacteria/mL in the sample or sample dilution. 1.4 This test method is intended to be used as a simplified field method where bacteriological laboratory facilities are not readily available. 1.5 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.