50% Explosion height

After data are collected via the up and down method 21 , the 50% explosion height (H s o, cm) is determined and the energy (E 5 o, J) of ball dropped at 50% of the explosion height is calculated. Test results should be recorded as in the example in Table 3.6. 

The 50% explosion height (H s o, cm) is calculated using following equation,... 

At the 50% explosion height determined via the up and down method, the results are repeated 10 times or 40 times and the sensitivity of the sample is estimated with 0/10, 10/10 or 20/40. 

As the result of these investigations, the 50% explosion height determination method using the up and down technique was confirmed as a superior test method. It requires the fewest trials, it yields highly reliable results, and it is accurate. The 50% explosion... 

In the case of the drop hammer test using the up and down method, the drop height is decreased at certain intervals when the sample explodes or correspondingly is increased at certain intervals when the sample dose not explode. This procedure is carried out through several iterations. As the result of these trials, test heights are concentrated near the 50% explosion height, and it becomes possible to estimate the 50% explosion height. 

The method of measuring the 1/6 explosion height suffers from poorer reliability and unknown accuracy when compared with 50% explosion height measurement with the up and down method. 

The standard deviation ( o ) of a normal distribution is also presumed for trials for the 50% explosion height (Hs ) with the up and down method. The 1/6 explosion height can be estimated using these two values. Accordingly it seems better to use the up and down method to find the 1/6 explosion height. 

This test seeks to evaluate the sensitivity of solid substances to impact. For these purposes, the 50% explosion height (where the explosion occurs at 50% probability) is measured by dropping a steel ball onto a standard mixture made of some standard substance and a flammable substance. The sample is judged "go" (for explosion) or "no go" (for no response) at 50% probability by dropping the same steel ball onto a sample mixture made with sample in question and a flammable substance from the... 

The 50% explosion height (H r, o ) should be determined using the same procedure as (a.l). In this case, the steel ball 40mm diameter (about 261g) should be used. 

Test results are analyzed and the 50% explosion height (Hsu) as well as standard deviation ( a ) of log H determined. 

D5.1 The 50% explosion heights (H so) for the mixtures of potassium nitrate and red phosphorus and of potassium chlorate and red phosphorus... 

Well No. Total Depth of Well (ft) Total Depth of Casing (ft) Explosive Height m Sand Tamp Depth m Explosive Used (lb)... 

Table 29. Drop hammer test with a 2 kg hammer, non-explosive height in cm for 50 trials...

The symbol ( ) shows that the non-explosive height is higher than I30 cm, but could not be determined. 

The above procedure produces blast parameters applicable to a completely symmetrical blast wave, such as would result from the explosion of a hemispherical vessel placed directly on the ground. In practice, vessels are either spherical or cylindrical, and placed at some height above the ground. This influences blast parameters. To adjust for these geometry effects, and 7 are multiplied by some adjustment factors derived from experiments with high-explosive charges of various shapes. 

A truck carr) ing two tanks containing a very unstable and hazardous gas is involved in an accident that results in tlie consecutive explosion of the tanks -one innncdiately, the second approximately a minute later. The total mass of tlie emission resulting from the explosion of each tank is 30,000 g. The wind velocity is 1 m/s from the north, and tlie effective height of emission is 30 meters at the time of tlie accident. Calculate the concentration of tliis gas at 500 meters south but 100 meters east from the site 10 minutes after tlie explosion of tlie first tank. Assume tliat stability category D applies. 

The required relief area. A], for a volume V] = 1 cu m obtained from the nomograms. The same reduced explosion pressure, P,.ed, and same static activation pressure, Psiau of the relief device are the same for both volumes Vi and V2, and therefore constant. WTien the mechanical strength of the vessel, is changed, the maximum volume and height will change with the hazard class, St-1, St-2, or St-3. 

Evaluation of chromatograms la 133ff Evaluation, peak area or height la 31,33,40 -, optical trains la 30, 39 Evipan la 339,343 Excitation to fluorescence la 10,12,20,37 Explosion resulting from reagent residues la 82,253,261,315,365 Explosives lb 49,244,407-409 Exposure to vapors la 86... 

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