PROGRAMMING THE AREARAE
4-33
4.7.8 Change Pump Duty Cycle
A duty cycle is the ratio of the time the pump is on during 10-
second periods. For example, a 30% duty cycle means that the
instrument turns the pump on for three seconds, and then turns
the pump off for seven seconds. You may control the time the
pump is on during the specified 10-second period. Currently,
users may only set the duty cycle from 20% (2 seconds) to
100% (10 seconds) with 10% (1 second) increments.
Increasing the duty cycle gives the instrument more time to
clean its lamp, reducing lamp contamination and slowing 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 and calibration 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 =” appears 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 the specified value has been selected, press [MODE]
for three seconds. The screen “Value Changed?” appears.
If no values have been changed, the unit advances to next
menu option, “Change Pump Speed?”
4. If values have been changed, you may save changes when
the screen “Save?” appears by pressing [Y/+]. A “Save!”
message confirms changed settings have been saved.
5. If you decide not to save changes to settings, then press
[N/-] when “Save?” appears. The AreaRAE Steel advances
to next menu option, “Change Pump Speed?”
