NUS-7
NUS-7 K03/0617
Seite 17
P28: a Echo loss indication
FACTORY DEFAULT: 0
a
Echo loss
indication
Remark
0
Delayed indication
During short echo-loss (for the period of twice the time set
in
P20
) analogue output will hold last value. After this
period the current value according to the setting in
P12
and via HART ERROR CODE 2 will be transmitted.
1
No indication
For the time of echo-loss, analogue output will hold last
value.
2
Filling simulation
Loosing echo during the filling process, transmitted value
will increase according to the filling speed set in
P26
3
Immediate
indication
Loosing echo the current value (according to the setting in
P12
) and the
ERROR CODE 2
(via HART) will immediately be transmitted.
4
Empty tank
indication
Echo-loss may occur in completely empty tanks with a
spherical bottom due to deflection of the ultrasonic beam,
or in case of silos with an open outlet. In such cases it
may be useful to indicate empty tank instead of echo loss.
P29: Blocking out of disturbing object
FACTORY DEFAULT: 0
One fixed object in the tank, disturbing the measurement, can be blocked out. By
the use of the Echo Map (
P70
) the precise distance of disturbing object can be
read out. This value should be entered in this parameter.
P31: Sound velocity at 20
C (m/s or ft/s depending on P00(c)
FACTORY DEFAULT:: 343,8 (m/s), 1128 (ft/s)
This parameter should be used if the sound velocity in the gases above the
measured surface differs largely from that of in the air.
This is recommended for applications where the gas is more or less homogeneous.
If it is not, the accuracy of the measurement can be improved using 32-point
linearisation (
P48
,
P49
).
For sound velocities in various gases see section “Sound Velocities”.
HART
Current output
Holding value
Holding value
Error Code 2
Current 22mA
P12=2
Holding last value
P12=0
Current 3,8mA
P12=1
Echo loss
Echo LED goes out
2 * ”P20” time
