ISO 10349-11:1992 download.Photography — Photographic-grade chemicals — Test methods — Part 11: Determination of specific gravity.
1 Scope
This part of ISO 10349 specifies a general test method for the determination of the specific gravity (relative density) of solutions used in photographic processing.
2 Normative reference
The following standard contains provisions which, through reference In this text, constitute provisions of this part of ISO 10349. At the time of publication, the edition indicated was valid. All standards are subject to revision, and parties to agreements based on this part of ISO 10349 are encouraged to investigate the possibility of applying the most recent edition of the standard indicated below. Members of IEC and ISO maintain registers of currently valid International Standards.
ISO 10349-1:1992. Photography — Photographic- grade chemicals — Test methods — Part 1: General.
3 Hazards
See ISO 10349-1 for general hazard warnings for the handling of chemicals.
4 Apparatus
4.1 Hydrometer, constant mass, variable- displacement calibrated hydrometer with 0,001 subdivisions at 15,6 °C (60 °F) relative to distilled water at 15,6 °C (60 °F).
NOTE 1 Most common hydrometers are calibrated for use at 20 C. Hydrometers calibrated at other temperatures may be used with appropriate corrections. A hydrometer calibrated at 25 C, the temperature for the determination, would be particularly convenient.
4.2 Hydrometer cylinder, clear glass vessel of approximately 250 ml capacity, cylindrical in shape and taller than the hydrometer.
4.3 Constant-temperature water-bath, with pump
and heating system designed to maintain a circulating current and constant temperature (± 0,05 °C). The bath shall be deep enough to keep that part of the hydrometer cylinder which contains the sample below the surface of the water. The bath temperature shall be set at 25 °C.
5 Sampling
See ISO 10349-1.
6 Procedure
Pour a test portion of 100 ml of the test sample into the hydrometer cylinder (4.2). Place the hydrometer cylinder with the test portion in the water-bath (4.3) and allow it to equilibrate to the bath temperature. Carefully lower the appropriate hydrometer (4.1) into the cylinder and allow it to float freely.
Read the specific gravity as the division on the hydrometer scale at the bottom of the solution meniscus.
NOTE 2 To convert the specific gravity measured using a hydrometer calibrated at 15.6 °C to a specific gravity at 25 °C, dMde the result by 1.001 97 (the ratio of the density of water at these two temperatures).
7 Test report
The test report shall specify the method used and the test result obtained.
It shall also mention all operating details not specified in this part of ISO 10349, or regarded as optional, together with details of any incidents which may have influenced the test result.
The test report shall include all information necessary for the complete identification of the sample.