A032-ET - International Laser Ranging Service

Event Timer A032-ETAfter performing of all preparatory procedures theaccessory panel has the appearance shown inFig.C-4. As shown, the event timer suggests themeasurement RMS resolution about 7 ps. Theserver setting is adapted to the highest-speedoperation (waiting time is zero); 6 events (includingStart event) will be measured in each cycle.The gate delay control is defined on the own panel(Fig. C-5). The gate delay is set to 1.5 µs and theincrement step isset to zero to avoidin this way thedelay variation.Fig.C-5The upper fraction corresponds to“Stop-Start” time intervals (theyare near to the period 3.1 ms ofcycle repetition) and the bottomfraction – to “Start-Stop” and“Stop-Stop” time intervals that aremuch smaller. Note that there areno any unexpected larger timeintervals that could indicate skipsof some measurement cycles.Zoom in for Y-axis allows seeingevery fraction of time intervals withbetter time resolution andcalculating their basic statistics.Specifically, Fig.C-7 shows that“Start-Stop” time intervals arevariable as compared to the muchmore stable “Stop-Stop” timeintervals (as was expected). Meanand RMS deviation of the “Stop-Stop” time intervals is about11,568.7 ns and 8.9 psrespectively.Fig.C-4.Under these conditions the measurement of about 10,000 inputevents during 1667 sequential cycles results in two separatefractions of time intervals between all pairs of adjacent events.Zoom in for X-axis makes it possible to see these fractions inmore details and separate the “Start-Stop” intervals (coloured inblue) from other ones (Fig. C-6).Fig.C-6Thus, the above measurementexemplifies that the A032-ETreally supports multi-stoppedmeasurement at 320 Hz cyclerepetition rate with RMS resolutionsurely better than 10 ps. Actuallythe cycle repetition rate can bemuch higher.Fig.C-736