1 edition of Measurement and reduction of noise from detonating cord used in quarry blasting. found in the catalog.
Measurement and reduction of noise from detonating cord used in quarry blasting.
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It is used in the blasthole as a long lead down-the-hole delay system to replace detonating cord downlines, or as a pigtail on down-the-hole delays used in conjunction with detonating cord. Shock tube systems, unlike some detonating cords, will not set off a primer and must always be used with a down-the-hole initiator and compatible primer. 3 Reducing the source impedance (if possible) gives two benefits: Reduction in thermal noise voltage Reduction in capacitive interference coupling (see later) Example: Using 20 kHz bandwidth, a 1 MΩ sample at room temperature generates thermal noise of 20 µV. Reducing the resistance to 10 kΩ would reduce it to 2 µV.
The Outlook for Blasting Caps, Squibs, Ignitors, Detonating Primers, Fuses, Detonating Cord, and Other Blasting Accessories for Explosives in . A primer, or catalyst, is another explosive set off by the blasting cap or detonating cord that quickens the reaction and increases the efficiency of the main blast (USACE ). Detonation of blasts is measured on the same order of magnitude as the chemical reaction and mechanical fracturing of the rock, typically in milliseconds.
Noise Reduction and Isolation. Controlling noise in measurement systems is vital because it can become a serious problem even in the best instruments and data acquisition hardware. Most laboratories and industrial environments contain abundant electrical-noise sources, including ac power lines, heavy machinery, radio and TV stations, and a variety of electronic equipment. Majan Mining, most often, detonating cord was used (Figure 5), though Nonel detonators were also used when blasting very close to sensitive structures. Various blast designs were used at the cause of the study, the variance centred on the delay pattern. When using the detonating cord, the Shot Delay Detonator (SDD) i.e. electric.
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Measurement and reduction of noise from detonating cord used in quarry blasting Paperback – January 1, by A. Viksne (Author)Author: A. Viksne. Measurement and reduction of noise from detonating cord used in quarry blasting.
[Washington, D.C.]: U.S. Dept. of Interior, Bureau of Mines, (OCoLC) Abstract. A series of tests were conducted by the Bureau of Mines to determine the best means of reducing noise generated by the detonating cord that is utilized for trunklines in quarry blasting.
Ten different types of detonating cord were tested and evaluated for their acoustic qualities. The results of the investigation showed that noise levels produced by "low-core-load-per-foot" detonating cord. Measurement and reduction of noise from detonating cord used in quarry blasting / By A.
(Andris) Viksne, Denver Safety and Health Technology Center (U.S.). and United States. Bureau of Mines. A series of tests were conducted to measure the acoustical characteristics of 10 different types of commercially available detonating cord.
Test measurements were made using impulse sound level meters, recorded on tape, and analyzed for amplitude and frequency content. A number of curves are presented showing the variation in the sound pressure level with explosive core load in grains per.
There are five principal sources of air overpressure from blasting at surface mineral workings: The use of detonating cord which can produce high frequency and hence audible energy within the air overpressure spectrum.
Stemming release, seen as a spout of material from the boreholes, gives rise to high frequency air overpressure. detonating cord) delay assemblies made by ‘the DuPont Co are described in pp & They are essentially ““nonelectric MS(microsecond) delay caps”~ The LEDC produces very little noise on detonation and for this reason can be used in highly populated areas.
It is usually recommended for operations where bottom-hoIe. In order to measure detonation velocity a measuring instrument Explomet-Fo (by Kontinitro) was used. It is an electronic timer for which measuring is initiated and stopped by light signals .
Quantum constraints on noise 1. Heuristic weak-measurement noise constraints 2. Generic linear-response detector 3. Quantum constraint on noise 4. Evading the detector quantum noise inequality B.
Quantum limit on QND detection of a qubit V. Quantum Limit on Linear Ampliﬁers and Position Detectors gives lesser noise levels compared to detonating cord initiated blasts. Studies conducted by Sastry and Chandar  showed a considerable reduction o f 5 to 10 per cent in noise levels with shock tube.
1) IED - instantaneous electric detonator. This has no delay element and is used, for example, to initiate detonating cord at the start of a blast.
2) MS - IT is the same basic construction as the IED but includes a delay element. The delay interval is measured in milliseconds (MS). Generally used for bench blasting in a quarry. Measurement and reduction of noise from detonating cord used in quarry blasting.
US Bur. Mines, Rep. Invest., Issue32 pp. Google Scholar. VVAA, VVAA, Linee guida relative ai criteri per la classificazione acustica dei territori comunali. APAT. be determined by measurements of the thermal (Johnson) noise in a series of resistors, while e will be determined by measurement of the shot noise in a weakly illuminated photodiode.
This experiment consists of three steps: • First, you calibrate the preamplifier and filters to obtain their gain vs. frequency response (see figure ). 2 Stripping overburden at Wheal Hughes copper mine opencut, Moonta. (Photo ). blasting of cornices increases efficiency, boring holes along the presumed tension line exposes the ava-lanche blaster to considerable danger.
Safety in borehole blasting depends critically on: 1. The blasting crews ability to judge correctly the safe working line. techniques for working with this high explosive (See Chapter 5 - Detonating Cord). The sudden noise caused by blasting can give rise to substantial complaints from people living in the proximity of opencast mines, quarries or construction sites.
A measurement technique and simple prediction method are proposed which can be effectively applied for community exposure planning and reduction. drilling and blasting. Key words: Detonation, Initiation, Hole, Detonation Cord, Explosive, Nonel.
Introduction The limestone in Volljak represent a significant national amount and are among the most qualitative in the Balkan region. Based on the physic - mechanical and chemical holdings, they can be used in. If explosive detonating cord is to be used to detonate the blastholes, it should be covered with suitable aggregate material.
It is always advisable to use a Nonel initiation device to help reduce airblast generation. As is the case with ground vibration, the selection and use of delays can strongly influence the airblast, because sound in air.
Detonating cord Detonating cord contains a core load of high explosive (usually PETN). It detonates at ab ft. per second.
Detonating cord is made with various weights of PETN per ft. You fashion your sound jacket to the dividing wall covering the 2 by 3 foot hole in the wall. When you have it secured, you take another sound measurement and you find the reading is now dB.
The decibel drop is dB. To determine the coefficient (C) of sound reduction, use the decibel drop (d) in the following formula. Controlling noise in measurement systems is grounded cord, for example. An electrical fault Noise Reduction and Isolation.
2 Measurement Computing • 10 Commerce Way • Norton, MA • () • [email protected] • Figure Digital.Explosives are used in a number of industries and locations in Ireland. They are used extensively in underground mining and surface hard rock quarrying operations.
They are also used frequently in the construction industry for the development of new roads, excavation of ground for the foundations of buildings or basement areas and in demolition.the effects of noise.
All Micro-Measurements strain gage instruments and data systems are equipped with this important feature. The following procedure can be used to troubleshoot a system for noise: 1.
If not already known, determine the tolerable levels of noise in output units (millivolts, inches of deflection.