Edwards ELD500 Series

D135-10-880C - Operation
Page 60
Pinpoint
The tone of the acoustical signal changes its frequency only in a leak rate-window, Figure 27,
which ranges from one decade below the Trigger level 1 up to one decade above the Trigger
level 1. Below the window the tone is constantly low, above the window it is constantly high.
Example: The Trigger level 1 is 4 x 10
-7
mbar l/s. So the window where the tone changes
reaches from 4 x 10
-8
mbar l/s up to 4 x 10
-6
mbar l/s.
Figure 27 Pinpoint: change of the frequency in the leak rate window (TR1=Triggerlevel 1)
Leak rate prop.
The frequency of the acoustic output is proportional to the reading on the bar graph display.
The frequency ranges from 300 to 3300 Hz. Refer to Scale linear/logarithmic for the
definition of the number of decades.
Setpoint
The tone is off as long as the leak rate is below the Trigger level 1. Above Trigger 1 the tone
varies proportional to the leak rate, Figure 28.
Figure 28 Setpoint: change of the frequency above the trigger level 1 (TR1= Trigger level 1)
Trigger alarm
As soon as the leak rate increases above trigger level 1, a multi-tone signal is generated. The
tone does not vary with the leak rate.