MagTek InSpec 9000-2005 - Manual (Page 30)

InSpec 9000-2005 Encoded Card Tester
20
PARAMETERS
When a card is read, the Tester checks six important ISO parameters, which are presented
graphically, and color coded as green, yellow, and red. There are two sets parameter limits: one
for new cards and one for returned cards. New cards are cards that have been encoded but have
not been used. Returned cards are cards that have been encoded and issued, and usually used in
practical applications, and returned for testing.
ISO Limits and Measurement Uncertainty
The ISO Limits specified under the View menu are a composite of two ISO specifications: 7811-
2 and 7811-6. These values are the widest ISO limits of both specifications. They were selected
because LoCo and HiCo values are different, and Readers in the field read reliably with cards
encoded within these combined limits.
As with any machine, there are also tolerances, or measurement uncertainties, ascribed to the
Tester. Measurement uncertainty limits may be found on the “ISO Limits” screen that is
accessed from the Limits Menu. The measurement uncertainty is at the bottom of the screen.
Amplitude
The signal amplitude is the resulting voltage as the read head passes over the flux transitions on
a track. The measure of signal amplitude is stated as a percentage of the Reference Signal
Amplitude.
The value of the reference signal amplitude is traceable to the Primary Standard as established
by the United States National Institute for Standards and Technology (NITS), formerly the
National Bureau of Standards. Figure 3-7 shows the reference amplitude and the related
boundaries for within spec, marginal, or out of spec. These values as well as the values for the
other parameters below are listed in Appendix C (from 7811). Composite values (from 7811-2
and 7811-6) are listed in the ISO Limits under the View Menu.