user need not select a specified time for the data sample to occur but may cause the test and measurement instrument to automatically vary the sample times between the adjustable periods for example the user may be able to select a probability function such as that illustrated in fig7 in that figure a first sample period is illustrated at ts 1 and the conventional sample period for the second sample is illustrated at tsn between ts 1 and tsn is illustrated a probability function showing a probability that a sample u201c n u201d may be taken at any particular time between ts 1 and tsn illustrated here is the first half of a gaussian distribution although other distributions are possible for example other probability functions may include cosine laplace linear uniform or random these probability functions may be implemented by look up table or by a real time calculation using a probability distribution function pdf formula in other words because so many samples of data may be collected as described above varying the sample times between different sample data capture periods may allow the user a higher probability of detecting transient events especially those transient events that are periodic and have a frequency that aligns with the processing times tp 1 tp 2 etc of fig4 for example the user may control the limits of excursion for the sample timing capture variation for example the user may specify that the second capture period should not occur before 10 25 of the processing time of the previous data has passed other limits are also possible the change in the sample time may be in relation to the processing.