However, the ASTM standards D 6938 and D 2950 give a formula to compute the gauge precision by the slope method, which requires the use of the prescale factor.
The prescale factor is typically not needed by the gauge operator. In other words, the count that a gauge displays is the total number of ionization events measured by the gauge divided by the appropriate prescale factor. In order to scale the count values to a reasonable number of digits, Troxler devices use prescale factors when performing measurements, standard counts and any other diagnostics count.
