howto:avoid_pile_up_effect_in_flim_measurements
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howto:avoid_pile_up_effect_in_flim_measurements [2015/03/26 12:08] – [Measurement of Pile Up Limit] admin | howto:avoid_pile_up_effect_in_flim_measurements [2015/03/26 12:09] – admin | ||
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- | ===== Measurement of Pile Up Limit ===== | + | ===== Measurement of the Pile Up Limit ===== |
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* For detection of the pile up limit the count rate displayed in the Time Trace below the FLIM image is used. | * For detection of the pile up limit the count rate displayed in the Time Trace below the FLIM image is used. | ||
* A red line indicates the count rate limit which is 10% of the laser repetition rate. | * A red line indicates the count rate limit which is 10% of the laser repetition rate. | ||
- | * The **" | + | * The **" |
* At a pixel dwell time of 10µs each pixel is displayed as one point in the time trace. At a pixel dwell time of 1 µs the average of 10 pixels are displayed as one point in the time trace. | * At a pixel dwell time of 10µs each pixel is displayed as one point in the time trace. At a pixel dwell time of 1 µs the average of 10 pixels are displayed as one point in the time trace. | ||
* During the Test FLIM measurement the laser intensity is set that the time trace is only at rare instances hitting the red line. | * During the Test FLIM measurement the laser intensity is set that the time trace is only at rare instances hitting the red line. | ||
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+ | ===== Calculation of the count rate per pixel to determine the Pile-Up effect | ||
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+ | For an already acquired FLIM measurement it is possible to determine the count rate per pixel to determine if a pile-up effect is present. | ||
+ | Procedure: | ||
+ | * Calculate the exposure time per pixel: Multiply the number of frames with the pixel dwell time | ||
+ | * Determine the number of photons via the data reader (right mouse click) in a very bright pixel within the FastFLIM image | ||
+ | * Calculate the count rate for this bright pixel: Divide the number of photons per pixel by the exposure time per pixel |
howto/avoid_pile_up_effect_in_flim_measurements.txt · Last modified: 2015/06/03 15:11 by admin