AVF7000 Operation Manual
OP7000.1.1.7.R12ENG
13
9.3 Field Application
Two situations will frequently happen at site:
A. No flow, it displays value.
B. Flow, it displays zero.
Reasons for problem A
: vortex get interfered by outside environment, keeping receiving interference signals. In the
picture below, interference signal is more than vortex’s threshold value. So vortex displays value. To solve this problem,
interference signal should be smaller than threshold value.
V
Th e Th re sh o l d
In te rfe ri n g Si g n a l
Reasons for problem B
: flow frequency is very low, see the flow signal below. It’s lower than threshold value, leading
to measurement failure. To solve this problem, flow signal should be bigger than threshold value.
V
Fl o w Si g n a l
Th e Th re sh o l d
Then how to adjust interference signal and flow signal?
The solution lies in signal amplification. Signal amplification adjustment is ”2000~2000000”.
Default amplification:
If measuring medium is liquid, it’s 5000.
If measuring medium is gas or steam, it’s 80000.
Amplification adjustment method:
☆
Magnification can be divined into two parts:
amplification factor and magnification gain.
Magnification factor is in “Max AMP”while magnification gain in “AMP. Channel”.
If amplification is 5000, amplification factor will be 500 and amplification gain 10
1
, namely 500*10
1
=5000.
Amplification factor Amplification gain
(Range: 200~2000) (CH1=10
1
; CH2=10
2
; CH3=10
3
)
☆
To solve problem A
: decrease amplification factor. Suppose amplification is 5000 now, change amplification factor
(
Max AMP
) as 400 but keep amplification gain (
AMP.Channel
) the same (CH1). Then amplification is 400*10
1
=4000. If
vortex still displays unusually, adjust amplification factor again.
☆
To solve problem B
: it happens to be on the contrary of A, namely adjust amplification from 5000 to 30000. Then:
Change amplification factor (Max AMP) as 300;
Change amplification gain (AMP. Channel) as CH2;
Amplification number is: 300*10
2
=30000
☆
In conclusion, amplification has to be set according to actual condition, making vortex displays properly, namely it
displays zero when there is no flow and displays correct values when there is flow.
Max AMP
500
AMP.Channel
CH1
