5.1 General Utility: 

5.1.1 This practice is suitable for research, quality control, specification testing and process control.

5.1.2 It is useful to define and verify the reactivity of non-foam polyurethane formulations.

5.2 Limitations: 

5.2.1 Operator-to-operator variability and lab-to-lab variability can be significant.

5.2.2 The variability of this practice is dependent on the equipment used to measure the gel time. It is recommended that the testing laboratory and the client agree on the equipment and the conditions to be used that include the following:

5.2.2.1 Gel Tester and gel point criteria,

5.2.2.2 Speed/rpm of the mixer,

5.2.2.3 Type and shape of the mix blades,

5.2.2.4 Size and type (for example, shape, lined or unlined) of container for mixing the components and for measuring the gel time, and

5.2.2.5 The volume (or height) of material to be placed in the container for measuring the gel time and the depth of the measuring wire or spindle of the gel tester from the bottom of the container.

5.2.3 The estimation of precision in this practice is very limited. Users of this practice shall develop their own precision data to determine if these procedures meet their requirements.

5.2.4 It is possible that low-levels (ppm, ppb) of contaminants will not be detected using this practice.