5. GFS TOOLS SOFTWARE
Page 157
© 2007 DH Instruments, a Fluke Company
5.7.11
SAMPLE RATE
Several setup factors and the active flow rate determine the GFS sample rate. The sample
rate is the rate at which mass, time points are used to determine a new GFS flow, and the
rate at which the DUT flow is averaged. The mechanism used to determine the sample rate
automatically provides longer times for low flows and faster times for higher flows.
The equation and table below define how the sample rate is calculated. When sampling
starts and stops is based on the starting and ending %rdg tolerances and the target depleted
mass entry.
q
m
t
s
r
=
VARIABLE
DEFINITION
t
r
The time interval between consecutive GFS samples.
The GFS is capable of taking a maximum of approximately 12 samples per second.
The number of samples actually used is defined by the
[Setup] [Configuration]
[System] <Balance RS232 Poll Interval>
. The actual number of readings taken
from the balance governs the true minimum time between samples.
m
s
The
[Setup][Configuration]<Min mass change per GFS sample>
value.
q
Nominal flow target (g/s). This is not the instantaneous flow value.