Yokogawa RotaMASS 3-Series - Manual (Page 172)

7. pArAMETEr dESCrIpTION
7-100 IM 01R04B04-00E-E 8th edition March 01, 2011 -00 All Rights Reserved. Copyright © 2003, Rota Yokogawa
7.20 Slug detection (detailed Setup)
Slug detection
Not available if gas measurement
is ordered.
Detection of bubble flow.
After slug criteria has been reached, slug is supervised during slug
duration. If slug is still detected after slug duration has expired, the
selected action in
After slug is taken.
See below table.
Slug alarm select Select: Not apply, Apply
drive gain To read drive gain.
To set a suitable slug criteria the customer must know the drive gain
level of normal flow condition and of slug flow condition. This function is
suitable to evaluate this level.
Slug criteria Above this drive gain level slug flow is assumed.
Slug duration Duration time is designed to ignore short gas bubbles. Only after Slug
duration has expired the setting in After slug will be taken in account.
In normal slug application set slug duration to zero.
After slug Select: Measured value, Hold
If Hold is selected mass flow and density keep their value before
occurrence of the slug alarm and as long as slug alarm is detected.
drive gain damping Set drive gain damping time to get a constant drive gain level.
Gas application?
Yes No
Slug detection off
Slug alarm select = Apply?
Yes No
Drive gain > Slug criteria?
Slug detection off
Yes No
Duration active?
Yes After duration
Function active
Alarm off
Measurement
continued
Slug detection On
Alarm on
Measurement
continued
or value hold
Slug detection off
Alarm off
time
mass flow
drive gain
density
single
bubble
slug flow
duration time
mass flow, if
Hold
mass flow, if
Measured value
T88.EPS
Influence of slug on mass flow, density and drive gain :