Accusonic 8510+ series Reference Manual page 65

7-10 Accusonic Model 8510+ Series Flowmeter
icon on the HOME page. To display the path variables, press the Path icon on the HOME page. Only 1
page is available for the section variables, and 3 pages are available for the path variables. The variable list
below describes the measured variable as well as defines which screen the variable can be found:
FLOW SECT
LEVEL SECT
TEMP SECT
VOL
SECT
VEL
Vsound
GAIN
Detection
S/N (dB)
Gain %
TRAV
DELTA_T
The time-averaged value of the water flow, scaled in the required units.
If the parameter Flow Scaling is set to 1, the units will be cubic ft/s or cubic
meters/s.
The averaging is carried out using an Infinite Impulse Response (IIR) digital filter,
whose time is set by the System parameter FLOW AVE LVL (0 – 5). The Flow for each
section can be found on screen 0-1. The screen number is in the lower left corner of
the touchscreen display. The SUM OF SECTION FLOWS will be displayed at the
bottom of this page, for a one section flowmeter, the SUM OF SECTION FLOWS will
match the flow for SECTION 1.
The arbitrated time-averaged value of the Level in each section, which is used for
the calculation of flow. The averaging is carried out using an Infinite Impulse
Response (IIR) digital filter, whose time is set by the parameter LEVEL FILTER. The
level for each section can be found on screen 0-1.
The water temperature in each section, computed from the average velocity of
sound for each good working path in that section. It is computed using the
relationship for distilled water, corrected if necessary by a user defined offset; the
section parameter TEMP CORRECTION. This is displayed on screen 0-2.
The totalized flow for each section, scaled according to the Volume Scaling
parameter.
These values can be individually set or reset from the Section menus.
The maximum displayed value is 999,999 after which the display goes to zero and
restarts. This is displayed on screen 0-2.
The VEL is the value of the individual water velocity in feet/second or
meters/second, averaged over 8 readings.
A negative figure indicates reverse flow. This is displayed on screen 1-1.
The Vsound is the computed velocity of sound for that path (used for diagnostic
purposes) in feet/second or meters/second. This is displayed on screen 1-1.
The value of the Receiver gain, nominally in dB units. Maximum value 40
Equal to: 20 x log10 [Ratio of signal voltage at A/D converter: Transducer output]
0dB indicates a signal level of 1Volt peak to peak at the transducer terminals. This is
displayed on screen 1-2.
The letter E or Z indicates the signal detection method, either "Envelope" or "First
Negative".
The letter H indicates that the velocity reading has been "Held" The latest acoustic
signal is unacceptable, and the previous value for water velocity is being used for the
computation of flow. X indicates that consecutive acoustic signals for that path have
been rejected for a period greater than the parameter Max Bad Measures and the
path has failed or that the path is not in use. Displayed on screen 1-2.
S/N is the Signal to Noise ratio expressed in dB. Less than 12dB indicates a serious
noise problem, and that the data for that path will be rejected. Displayed on screen
1-3.
Gain % is the amplitude of the latest instantaneous signal, after amplification,
expressed as a % of full signal at the detector. Normally this value will be between
95 and 105. Displayed on screen 1-3.
The signal travel times in micro seconds (s), Forward (left column) and Reverse
(right column). The values are the total times less the Signal Delays and represent
the travel times of the signals through the water. Displayed on screen 1-4.
The time difference, in nano seconds (ns), between the instantaneous forward and
reverse signal travel times. A negative figure indicates reverse flow. Displayed on