PROGRAMMING AREARAE-Gamma
4-32
4.7.8 Change Pump Duty Cycle
A duty cycle is the ration of the time the pump is on for ten-
second periods. A 30% duty cycle would mean that the
instrument turns the pump on for three seconds, and then turns
the pump off for seven seconds. Users may control the time
the pump is on for the specified ten-second period. Currently,
users may only set the duty cycle from 20% (two seconds) to
100% (ten seconds) with 10% (one-second) increments.
Increasing the duty cycle gives the instrument more time to
clean its lamp, reducing lamp contamination, which slows the
rate of signal degradation.
A disabled duty cycle means the pump is always on. The
pump duty cycle is disabled when the reading is higher than
2.0 ppm and is enabled when the reading drops below 1.6
ppm. Users may also disable the duty cycle by setting the duty
cycle to 100%. The duty cycle is also disabled during system
warm-up, PC communication mode, programming mode, and
diagnostic mode.
1. At the “Change Duty Cycle?” display, press [Y/+] to enter
this menu, otherwise press [N/-] to advance to the next
menu option “Change Pump Speed?”
2. Next, the screen “New Duty Cycle =” will appear with a
percentage value following it. If the percentage is less than
100%, then press [Y/+] to increase the duty cycle by 10%.
If the percentage is greater than 20%, then press [N/-] to
decrease the duty cycle by 10%.
3. Once specified value has been selected, press [MODE] for
three seconds. The screen “Value Changed?” will appear.
If no values have been changed, user will advance to next
menu option “Change Pump Speed?”
4. If values have been changed, user may save their changes
when the screen “Save?” appears by pressing [Y/+].
“Save!” will confirm changed settings have been saved.
5. If the user decides not to save changes to settings, then
press [N/-] when “Save?” appears. User will advance to
next menu option “Change Pump Speed?”
