Plastics — Measurement of resistivity of conductive plastics
Specifies the requirements for the laboratory testing of the resistivity of specially prepared specimens of plastics made conductive by the incorporation of carbon black. The test is suitable for materials having a resistivity of less than 104 Ohm x m. A stable d.c. current is passed between electrodes at the ends of a test piece. A schematic diagram of the test circuit is given. The voltage drop…
The requirements specify a series of plastic cylinders having a tapered ore non-tapered form. The capacity is in the range from 25 ml to 5000 ml. For non-opaque beakers the graduation is specified. The construction, dimensions and material are described. The annexes deal with the test for ionic material extracted by water and with the flexibility test.
Six preferred sizes are defines by their internal bowl diameter. General design are shown in a figure and the dimensions are tabled. The material shall be general non-brittle plastics. Annex A concern the determination of resistance to extraction of ionic material by water, Annex B describes the flexibility test.
Laboratory glassware — Density hydrometers for general purposes — Part 2: Test methods and use
The determination of the density is specified considering the general procedures. Apparatus and readings of the density and temperature are described and also the application of the corrections. In drawings the construction and the demensions of suitable vessels are shown.
Laboratory glassware — Graduated pipettes — Part 2: Pipettes for which no waiting time is specified
The special requirements deal with three international acceptable series of pipettes (type 1, 2, and 3) which are adjusted to class A or class B accuracy. Capacity, graduation, delivery times are specified.
Laboratory glassware — Graduated pipettes — Part 3: Pipettes for which a waiting time of 15 s is spe...
The special requirements deal with a international acceptable series of pipettes with comparatively large jets with waiting time of 15 s for compensaiting the possible effect of shorter delivery times. They are adjusted to class A accuracy.
Laboratory glassware — Graduated pipettes — Part 4: Blow-out pipettes
The special requirements concern the capacity, graduation, figuring, delivery and identification. The lower end of the scale and the delivery time are tabled for the nominal capacity. The handling of the pipettes at the measurement is specified.
Laboratory glassware — Density hydrometers for general purposes — Part 1: Specification
The requirements for basic series and sub-series of glass hydrometers of constant mass without built-in thermometer are specified. They are graduated to indicate density at 20 degrees centigrade and 15 degrees centigrade, respectively. Standard categories of surface tension are tabled in annex A, recommended stem diameters in annex B.
