Content copyright ESN labs 2016


YouTube Videos of the Phochron in action. Test a box camera in under two minutes! Check the video page.

Calibration Self Testing

The Phochron XA has a built in mode of operation where the accuracy and the calibration of the light source and of the photo sensors  that make the speed measurements.

During the testing of various cameras, you may find that the results show that your shutters are very inaccurate. This can make you doubt the tester ‘s accuracy.

The self-check mode of the Phochron device uses the built-in light source to send a pulse of light that the sensor then measures. This pulse of light is 1/10,000 second long. You can immediately see how well the tester can measure and resolve a light pulse this short. It is as if you are testing a perfect shutter that fires at 1/10,000th of a second.

Testing the single sensor of the Phochron XA. Hold the light source about 2 inches from the front sensor hole. The measurements will start as soon as the sensor put in place.

The results of the single sensor test show it is resolving the .100 ms pulse very well.

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Here are the results from a dual sensor check.

Dual sensor checking is done by pointing the light source at the pair of sensors on the external sensor module as selected by the slide switch on the back of the module.

Use the menu select buttons to enter the calibration check mode

Readings from .093 to .107 are considered normal.  You may notice that the numbers change slightly depending on how close the light source is placed.