HYDAC HMG 3010 - Manual (Page 39)

HMG 3010 Page 39
Edition 11/2011 - V04 R01 Part No.: 669855
Sampling rate
This item enables you to set the rate at
which the HMG reads a measured value
from the sensors and saves it in the internal
memory. A measurement curve may com-
prise up to 500,000 measured values. Se-
lecting 1 ms, for example, means that 1000
measured values per second are taken and
saved for each connected measurement
channel.
Use the arrow keys ( ▲ ) and ( ▼ ) to scroll
through the various settings for the sampling
rate. At the bottom of the display you see
information on the resulting recorded data
(number of data records and memory us-
age). If you select an invalid setting, mean-
ing that the sampling rate selected by you
would exceed the 500,000 maximum, you
are shown a message in lieu of the recorded
data describing the invalid setting made by
you.
The sampling rate selected depends primar-
ily on the measurement task at hand. A
sampling rate of 1 s is probably sufficient for
monitoring the temperature in a hydraulic
tank, as temperature changes generally pro-
gress slowly. If, however, you want to track
extremely rapid system-induced pressure
surges, which generally occur in the milli-
second range, you have to work with a sam-
pling rate of 1 ms or less.
HYDAC HSI pressure transmitters with
automatic sensor detection are capable of
tracking rectangular pressure pulses (theo-
retically occurring in a time of 0 s) less than
0.5 ms apart.
This means that simply setting a sampling
rate of 0.1 ms is not sufficient to capture
pressure surges occurring faster than 0.5 ms
apart. A suitable dynamic pressure transmit-
ter also has to be used.