MINE SWEPT SOFTWARE

The sweep rate can cause frequency-related errors if it is incorrect. If we set our sweep rate at 2 oct/min (two octaves per minute), then it would take three minutes to complete the sweep, as there are six octaves between 10Hz and 640Hz: If we set our sweep rate at 2 dec/min (two decades per minute), then it would take one minute to complete the sweep, as there are two decades between 10Hz and 1,000Hz:Īgain, suppose our sweep range or frequency range was from 10Hz to 640Hz. Suppose our sweep range or frequency range was from 10Hz to 1,000Hz. 10Hz and 20Hz are one octave apart, 10Hz and 40Hz are two octaves apart, and so on. Two frequencies are one octave apart when one frequency is double the frequency of the other. The frequency width can also be measured in octaves with a logarithmic rate. There is one decade between 10Hz and 100Hz, two between 10Hz and 1,000Hz, and so on. With a logarithmic sweep rate, less time is spent at higher frequencies than at lower frequencies because more cycles occur every second at higher frequencies.įor a logarithmic rate, frequency width can be measured in decades, or a factor of ten. When the sweep rate is logarithmic, the controller accomplishes the same amount of cycles at each frequency. We could also define the amount of time to complete the entire sweep. For example, we could set the controller to sweep over 1,000Hz in one minute (1,000Hz/min sweep rate). The frequency width is measured in hertz (Hz) for a linear sweep rate. When the sweep rate is linear, the controller spends the same amount of time at each frequency.

A duration of two (2) sweeps will start at 30Hz, sweep up to 100Hz, and then sweep back to 30Hz.Ī test standard may define the number of sweeps along the lines of “transition from 30Hz to 100Hz and back to 30Hz a total of 7 times.” In VibrationVIEW, you would set a duration of 14 sweeps to meet this standard.Īcceleration test profile with different sweep rates. A duration of 1 sweep will start the sine tone at 30Hz and sweep up to 100Hz. The default sweep range is 30Hz to 100Hz.

MINE SWEPT SOFTWARE

You can run a sine sweep test with the VibrationVIEW Sine software module (free demo). The test could also be defined so that the sweep began at the high frequency and ended at the low frequency. Then, it would increase the frequency over time until the controller reached 1,000Hz. The controller would start the test by shaking the product at a rate of 30Hz. Consecutive sweeps in the same direction (loop)įor example, consider a sweep range of 30Hz to 1,000Hz.Sweep back and forth between the min and max frequencies.A single pass from the highest to the lowest value (sweep down).A single pass from the lowest to the highest value (sweep up).In this case, the sweep range defines the sine test profile because it determines the minimum and maximum frequencies of the sweep.Ī sweep can be defined in several ways, depending on the software used to control the sine test: Sweep RangeĮngineers often run sine tests as swept sine tones across a defined frequency range. Below, we outline two parameters engineers use to define a sine sweep test: sweep range and sweep rate. It was improved between the two world wars by the substitution of multi-plane otters for the earlier single otter used for spreading the sweep, and by better designs of cutters.In vibration testing, a sine sweep test helps determine a product’s resonant frequencies. This ran across the North Sea from the Orkney Islands to the Norwegian coast. This form of sweep was first developed in 1919 in the minesweeper Oropesa during the clearance of the northern mine barrage laid during the First World War (1914–18). This severed the mooring wire so that the mine floated to the surface where it was destroyed by rifle fire. As the wire came into contact with the mines' mooring wires, they slid along it until meeting a cutter. Near the end of the wire was an otter which forced it outwards as it was towed through the water, and at the end was a float to hold the wire at its fixed depth and prevent it sinking to the bottom. The wire was towed astern of the minesweeper with a kite fitted to the wire a short distance from the point of tow to keep the wire down to a fixed depth below water. It swept mines to the side of the minesweeper by means of a long wire fitted with wirecutters placed at intervals along the wire to cut the mines' moorings. A method of sweeping moored mines by a wire towed by a single minesweeper.

Mine swept