Velocity of PRVI 7,63 Mauser & DWM 403

alvin · 11-26-2009, 02:21 PM

The User Manual says 21 - 7000 fps. It also explained a little bit how it works: there are two windows on the top of the device, around 1 foot away. The device detects the object flying over the windows (space as defined by two "antennas"), and divided by time duration. So, in my imagination, the internal clock can measure duration from 143 micro-seconds (1/7000) to 0.05 seconds (1/21).

Just use 21 fps as an example above. 56 fps is similarly reasoned. Different value though.

Why didn't they make a clock which can measure larger duration range, for example, 1 second, so this device could detect 1 fps speed..... I don't know. Probably because of cost? They can only sell for so much. At the low speed end, the manual claims it can meaure speed of airsoft paintballs, 21 fps or 56 fps is probably good enough for the purpose.

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11-26-2009, 02:21 PM	#6
alvin User Join Date: Jul 2007 Location: US Posts: 3,843 Thanks: 132 Thanked 729 Times in 438 Posts	The User Manual says 21 - 7000 fps. It also explained a little bit how it works: there are two windows on the top of the device, around 1 foot away. The device detects the object flying over the windows (space as defined by two "antennas"), and divided by time duration. So, in my imagination, the internal clock can measure duration from 143 micro-seconds (1/7000) to 0.05 seconds (1/21). Just use 21 fps as an example above. 56 fps is similarly reasoned. Different value though. Why didn't they make a clock which can measure larger duration range, for example, 1 second, so this device could detect 1 fps speed..... I don't know. Probably because of cost? They can only sell for so much. At the low speed end, the manual claims it can meaure speed of airsoft paintballs, 21 fps or 56 fps is probably good enough for the purpose.