  Here the results of calculations of pulses in Cherenkov light detectors for
the Yakutsk array are presented. As long as the Vavilov-Cherenkov light is used
to calibrate signals in scintillation detectors at the Yakutsk array it is
vital for these measurements to be precise. The validity of measurements of the
signal Q(400) used as the estimation parameter at the Yakutsk array has been
confirmed. Our calculations show that the width of time pulses increases from
nearly 50 ns at a distance of 100 m from the shower axis up to 700 ns at 1000
m.
