lojmikak
Dołączył: 30 Sie 2010
Posty: 1597
Przeczytał: 0 tematów
Ostrzeżeń: 0/5
Skąd: olvovw
|
 Wysłany: Pon 15:09, 13 Gru 2010 Temat postu: tory burch sale Oscilloscope when the subject of a |
 |
|
When the oscilloscope spot the subject of a high precision calibration method
Getting away from the spot to the starting position to n +1 if there is a time-scale pulses of light points in the post-edge, then the first +2 to 2 +1 standard pulse when the light points will fall on the subject of the dark zone no longer appear, as shown in Figure 1. Obviously, when the standard 2 +2 pulse again appears in the spot light when the subject area, repeat the above process. This show displays a transition string of pulses,[link widoczny dla zalogowanych], each pulse train has n +1 or a pulse. Dragonfly 2 a, L1 [_0 =. . _lJj B, L # \), finishing a ten △ / (2 )=,[link widoczny dla zalogowanych]。/( 2) (3) @,, measurement technology 1992. № 6 from (2) can be seen that the value of △ f and inversely proportional to, △ 'reduce the value to increase : If close to T., At / (2n) and I in comparison to the small to negligible,[link widoczny dla zalogowanych], equation (3) can be rewritten as grains At/r1 / (2n) (4) type (4) When the left spot f 【l uniform standard relative error, the right is a device in the display screen on the ferry to see the relation between n pulses. know the number of burst pulses in n, we can determine the subject of the oscilloscope spot when the relative error. For example = 10At / T = 1 / (2 × to) = 0.05 = 20At / T = 1 / (2 × 20) = 0.025 = 100At = 1 / (2 × too) = 0.005 in the actual calibration , for short periods can be observed when the burst length of the standard approach does not directly count the number of n. specific approach is the choice of scan time is about to be 1000 times the shuttle cycle time scale, the time scale than the standard output device connected to the oscilloscope vertical input the oscilloscope display graphics in Figure 2. when the standard error of the bigger points of light, showing 』deleted IIlLlu duh L. Figure 2 the number of the more burst. adjustment of the oscilloscope time scale calibration components, so that the oscilloscope shows the pulse trains reduced and each burst is increased longer. The best situation is on the screen only shows a pulse train,[link widoczny dla zalogowanych], or no show pulse, pulse time scale which is completed during a scan of light point barrier in the case of dark areas mark . as long as the time scale calibration allows fine-tuning of the adjustment range, the oscillator is stable time scale,[link widoczny dla zalogowanych], can easily scale to precision control of light point, less than five per thousand. According to beat the principle of mixing the two signals with similar frequency after produce a new signal, the signal frequency:, = l. a I (5) with a cycle that: f = T. · / (A T.) = T. · T / (AO (6) for our applications, equation (6) in order to show the pulse crossing the instrument calibration cycle time scale, as has been the subject of the school when the oscilloscope spot cycle, t is the burst cycle. by (6) (29] the relative error can be exported to fAti / T = T / t. () can be seen that the longer the period t, the error is smaller. Error of factors: the stability of the oscillator time scales. oscillation circuit fine-tuning the regulation of components fineness and stability of supply voltage . time scale is a regulated power oscillator, the oscillation loop is designed to fine-tune the component design considerations for the calibration of the oscillation frequency, there is sufficient regulation of fineness, so the error is mainly contributed by the first factor. For a fixed frequency LC oscillator (SBT used in a type 5) and RC oscillator (sBD type used in such a 6) short-term stability can be achieved lO_.. when the standard oscillator as the local standard oscilloscope, designed with optional stability better components and circuit, the calibration of the integrated error control will not be difficult to achieve 0.5. According to equation (7), if the scan time to adjust the oscilloscope time scale for the spot cycle 100O times in the screen see the entire sweep process has several burst cycles, when the subject of the oscilloscope spot is a few thousandths of the error. Equation (7), the absolute value of △ is given in the forms that the impact of positive and negative results on the same} . How to determine the sign of △, screen display according to the shape to determine the pulse train. When is positive (To>), the burst shape in Figure 3 (0), when m is negative. <), burst shape as shown in Figure 3 (b) below. and 』LJC) in Figure 3 can be opened after adjustment time offset calibrator switch, verify the calibration results. For more than 0.1 seconds long question time-scales, n direct count method, according to equation (4) to determine the relative error, which is the outstanding advantages of this method. We used this method hundreds of SBD such as oscilloscopes 6 when a calibration standard, easy to operate quickly, the effect is very satisfied . References Jianghuan Wen, Sun sequel \
相关的主题文章：
[link widoczny dla zalogowanych]
[link widoczny dla zalogowanych]
[link widoczny dla zalogowanych]
Post został pochwalony 0 razy
|
|
