YOKOGAWA RAMC, User Manual

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<6. ELECTRONIC TRANSMITTER (-E)>
6-20
IM 01R01B02-00E-E 12th edition October 01, 2014 -00
All Rights Reserved. Copyright © 2003, Rota Yokogawa
6.2.14.3 Unsuitable applications
It is possible, that the Float-Blocking-Indication- Function does not work satisfactorily. This can be caused with
different factors which are explained briefly here. In these cases the function of the Float-Blocking-Indication is
not suitable for the respective application and it should be turned off.
Applications with gases
At applications with gases and float-damping it can happen, that the pulsating movements of the medium
(and with that of the float) are damped so strongly in the measuring tube, that the measuring signal lies under
the autozero value and a Float-Blocking-Indication is not possible.
Applications with high viscous media
If a high viscous medium should be used in the plant, the damping can get so high by the high viscosity of
the flow that the measuring signal lies below the autozero value, and a Float-Blocking-Indication is not
possible.
Applications with quiet flow
If the plant has an extremely quiet flow (gases or liquids) ,the supervision range can be limited in the lower
flow range. Normally greater flow (>30%) causes greater medium flow deviations. The duration of the
supervision can be put to 15 minutes to reach a longer supervision time.
6.2.13.4 Parameter setting
Error message (F41)
Code Meaning Remedy
08 Float blockage
Supervision time gone off Check float in tube, clean tube if necessary.
Deactivate float blocking indication or run Autozero function.
Factory defaults / Master Reset (F65)
The RAMC is adjusted at delivery (Factory Setting):
- F71 - 1 Float-Move-Detection OFF
- F72 - 1 Lower limit value of the supervision area 5 %
- F73 - 1 Supervision time (Time Out) 5 min
- F74 Autozero inactive Autozero value = 0
After Master Reset the following attitudes are given :
- F71 - 1 Float-Blocking-Indication OFF
- F72 - 1 Lower limit value of the supervision area 5 %
- F73 - 1 Supervision time (Time Out) 5 min
- F74 Autozero inactive Autozero value not changed
Damping (F21)
The selection of the damping value has no influence on the autozero value or the measurement value of the
Float-Blocking-Indication !