VEGA VEGASON 71 - D - Manual (Page 37)

VEGASON 71 - D 37
9.3 Definition of the operating range
The operating range can be limited in this mode by
programming of
-
operating range begin and
- operating range end.
Echoes outside this limitation are ignored.
Note
The operating range end should always be programmed
10 % > than the flume end.
9.4 Multiple echo reduction
It is possible to reduce the echo gain by an offset function
to gate out possible multiple echoes.
Reduction range (offset range) = 0.00 … 1.25
Practical values = 0.00 … 0.20
9 Optimization
9.5 Adjustment of the max. gain
The pulse-echo measuring system tries to detect an echo
by using the whole gain. This means, that in case of an
empty flume the gain can be bigger than required for the
useful echo when the flow is available.
This causes that sound reflections (false echoes) are
detected as useful echoes. It is useful to limit the control
range of the gain to avoid this.
Note
- The limitation can be adjusted from 0.03 V to 4.50 V, as
optimization up to 4.95 V.
- The optimum adjustment of this mode is only possible
when the flume is empty.
- For orientation a d is indicated on the display of the
measuring system, as long as with the actual gain, an
echo (false echo) is detected.
Programming example
Indication of the echo gain
• Enquire mode
1 - 20 in the MODEFIELD
• e.g. 2.00 is indicated in the PARAMETER FIELD, i.e. in
case of an obviously wrong indication of measured
values, a false echo is detected with a gain of
2.000
Limitation
• Enquire mode
1 - 21 in the MODEFIELD
• Program e.g. 2.30 as limitation in the PARAMETER
FIELD
• Then store with STO
Optimization
• Enquire mode
1 - 22
in the MODEFIELD
e.g. d 2.30 is displayed in the PARAMETER FIELD
• Activate the optimization with MOD-key
• Optimize with "+"-key, until d extinguishes
The optimization is made in 0.02 V steps.
Requirement for this adjustment is that with actually
available flow, a considerably higher gain is sufficient
(relate do above example
≈
2,50 V).
If during the optimization a modification in the other
direction is required, this can be realized with key "–".
Useful echo
Multiple echoes
The reduction (offset) depends on the
function and starts with the end of the
measuring window.
Programming example
Reduction and optimization to e.g. 0.20
Reduction
•
Enquire mode 1 - 12 in the MODEFIELD
• Program reduction 0.12 (V) in the PARAMETER FIELD
• Then store with STO
Optimization
•
Enquire mode 1 - 13 in the MODEFIELD
• Activate the optimization with MOD-key (the whole
parameter indication
0.12 flashes)
• Optimize with "+"-key, until e.g. 0.20 (V)
The optimization is made in 0.01 V steps
If during the optimization a modification in the other
direction is required, this can be realized with key "–".