Float Test

The float test is used to determine the consistency of asphalt at a specified temperature. One test method (ASTM D139) is normally used for asphalt that is too soft for the penetration test (ASTM D5, D217, D937, D1403 IP 50, 179, 310). 

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Float Test (ASTMD139). The consistency properties of an asphalt at a very low apphed force are indicated by this test. The test is normally used for those asphalts that are too soft for the penetration test. 

We have recently modified the Krause process by incorporating a heat treatment step which results in a novel process for surface texturing of Kapton polyimide (Somasiri, N. L. D. Speckhard, T. A. U. S. Patent Applied For). When the textured polyimide is subsequently metallized, again using the Krause process, good adhesion is obtained after exposure to the solder float test. 

When subject to 90° peel test, adhesion values of 7-10 lbs/in have been obtained under ambient conditions. Interestingly, the adhesion after the solder float test retained 4-6 lbs/in. This high adhesion is believed to be primarily due to the mechanical interlocking facilitated by the textured Kapton polyimide. 

Length end Duration of Floats Test(Gt5aae nod Dsuer von Sjprengatoff-Flammea Ptobe, in Ger). Sea Flame Teat... 

Float test ASTM D-139 Normahy used for asphalts that are too... 

The float test is used to determine the consistency of asphalt at as specified temperature. 

At applied voltage over 2.7 V, there occurs a significant decrease in capacitance and an increase in internal resistance. In fact the float test revealed that the AC/AC capacitor loses its capacitance (AC < 13 % up to 30 days) at... 

Figure 12.2 Water released from positive and negative electrodes after 50 h of float test.

There are different test methods available, which allow the characterization of the wicking behavior of fibrous assemblies, such as the canvas disk wetting test, the Draves test, the demand wetting test, and the Lennox-Kerr test or sinking float test. Kissa [101] reviewed these techniques and the theoretical basics of wetting and wicking of such fiber assemblies. Therefore we... 

Note The fiber float test is simple and quick to run. Keep in mind that the problem must be massive in order for the biocide application to be economical and to justify the program costs. 

Thermal Stress Solder Float Test Soldering temperatures expose PCBs to thermal and mechanical stress and may deform the PCB shape and cause premature degradation of the base material. Thermal stress inspection is performed to predict the acceptability of the PCBs after the assembly and rework process. FIH degradation, separation of platings or conductors, and base material delamination are induced or amplified by the thermal stress test. The PCB specimen is oven-conditioned to reduce moisture, placed in a dessicator on a ceramic plate to cool, fluxed, floated in a solder bath, and placed on an insulator to cool. Visual inspection for imperfections is followed by microsectioning of the PTHs and inspection under a microscope for integrity. Test coupons are typically used for thermal stress inspection. 

Two basic types of tests are conducted thermal stress or solder float tests, and thermal cycling tests. Both of these tests are intended to be accelerated tests for the PTH, not for the laminate the thermal stress test, in particular, is expected to severely degrade the laminate. The delamination test is similar to a solder float test, but is conducted at a lower temperature specified by the laminate manufacturer typically, a different fluid is required. 

It was concluded that the effective density is essentially the same as the density of the nonboiling liquidunder the test conditions. The float test, the pressurization tests, and the lack of a decrease in density near the surface of the liquid indicate that the vapor bubbles formed very near the surface. This indicates that the bulk of the liquid does not contain any vapor bubbles, which is why the effective density is the same as the nonboiling density. 

This antimony effect on battery performance is shown by the results of an accelerated floating test shown in Figure 18.17. Industrial batteries of the same type were used, with the only difference that the positive grids consisted of various alloys. The floating voltage of 2.23 V/cell was applied as usual for stationary batteries. The acceleration of the test was achieved by periods of heavy overcharge of 3 times 100 h at a 3-month lime interval. 

In Figure 18.18, results of floating tests on stationary batteries with selenium alloys are compared with tests published by the Swiss Post Office in 1976. For his well founded experiments, Gerber used industrial batteries supplied by several manufacturers. The grid material of these batteries contained about 10% antimony. Some results on stationary batteries equipped with lead—calcium alloys are also given in Figure 18.18. 

Figure 18.17 Accelerated floating test. Tubular cells, 280Ah. floating voltage 2.23 V/cell (Courtesy of the Swiss Post Office. Bern)...

Floating test (e) May-Grunwald test (f) Oven-spring... 

TABLE 12 Solder Float Test Results for Immersion Silver (Ag) Board Finishes After Exposure to Various Preconditions... 

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