High-speed video analysis in quarry blasting
As part of their commitment to employing the latest technologies, Exchem Explosives have recently invested in a high-speed video camera to help with blast optimization and problem-solving activities.
The camera selected for this task, an I-Speed 1GB model manufactured by Olympus Industrial, was chosen because it allows the capture of high-resolution images (800 x 600 pixels) at a frame rate of 1,000 frames per second and with a shutter speed of 1/1,000 of a second. This effectively means that the processes in the blast are frozen and can be followed in detail, revealing effects that are not normally visible to either the naked eye or with standard video footage.
The camera has been fitted with a remote control by Exchem, allowing the unit to be operated from distances up to 400m away. A range of lenses allows for high-quality images to be captured over distances ranging from 30m to 400m from the target.
To date the video has been employed for a number of tasks, including :
Exchem Explosives, Venture Crescent, Alfreton, Derbyshire DE55 7RA; tel (01773) 832253.
The camera selected for this task, an I-Speed 1GB model manufactured by Olympus Industrial, was chosen because it allows the capture of high-resolution images (800 x 600 pixels) at a frame rate of 1,000 frames per second and with a shutter speed of 1/1,000 of a second. This effectively means that the processes in the blast are frozen and can be followed in detail, revealing effects that are not normally visible to either the naked eye or with standard video footage.
The camera has been fitted with a remote control by Exchem, allowing the unit to be operated from distances up to 400m away. A range of lenses allows for high-quality images to be captured over distances ranging from 30m to 400m from the target.
To date the video has been employed for a number of tasks, including :
- examination of fragmentation mechanisms in blasts – for example, to look at the effects of geology
- determining the time between detonation of explosives and the arrival of the shockwave at the free face, along with the time to first face movement – this information can be used to help determine the optimum delay time between adjacent holes when using electronic detonators
- examining the source of oversize material in quarry blasts – oversize rock can easily be followed during the video due to the high frame rate and fast shutter speed
- determination of face velocities in conjunction with the software package FrontCalc.
Exchem Explosives, Venture Crescent, Alfreton, Derbyshire DE55 7RA; tel (01773) 832253.
